Objective Heaters

[Neil Kad]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I want to use an objective heater for my home-built TIRF. I have an Olympus
1.45NA objective and more temperature control would be nice.

What kind of objective heaters are used out there and is there anything I
need to watch out for?

Cheers

Neil

[John Oreopoulos]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Neil, I used the one from Bioscience Tools during my PhD days and had no issues. It was fairly straightforward to use, and I also had a home-built TIRF microscope with the same objective:

http://www.biosciencetools.com/catalog/Heaters_Objective.htm

No commercial interest.

John Oreopoulos
Research Assistant
Spectral Applied Research
Richmond Hill, Ontario
Canada
L4B 3L8
www.spectral.ca


On 2011-03-22, at 5:14 PM, Neil Kad wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> I want to use an objective heater for my home-built TIRF. I have an Olympus
> 1.45NA objective and more temperature control would be nice.
>
> What kind of objective heaters are used out there and is there anything I
> need to watch out for?
>
> Cheers
>
> Neil

[Greg Martin-8]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hey Neil et. al. --

    Bioptics (http://www.bioptechs.com/Products/OBJ_HTR/obj_htr.html) makes an objective heater that folks here at the UW have been using on a TIRF system for the last few years.  No interest, but since they haven't told me otherwise I assume it's working for that application....

    Streric hindrance is they only problem I've encountered with the Bioptics heater.

Be peace!  Greg.

Greg Martin

Keck Microscopy Facility
University of Washington School of Medicine
www.depts.washington.edu/keck

206-685-8784 (office)
425-344-2632 (cell)
----- Original Message -----
From: "Neil Kad" <[hidden email]>
To: <[hidden email]>
Sent: Tuesday, March 22, 2011 2:14 PM
Subject: Objective Heaters


*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I want to use an objective heater for my home-built TIRF. I have an Olympus
1.45NA objective and more temperature control would be nice.

What kind of objective heaters are used out there and is there anything I
need to watch out for?

Cheers

Neil

[Dan Focht]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Neil

There are significant differences in the design and operation of Objective Heaters.
I have studied this extensively and used the results of these studies to develop and produce the Bioptechs Objective heater system.
Our system is not just a copy of an idea it is the first commercial, patented, Objective Heater System.
Other companies have copied the idea of warming an objective but not the technology behind it.    
Here are a few of the differences between the Bioptechs and other companies products.

In my opinion as an engineer, the Bioptechs Objective Heater System provides the most efficient, accurate and safe means of objective temperature control.

•  Most efficient  - heat is transferred to the barrel of the objective by the highest efficiency conductive means by a thin film heater directly in contact with the most thermally conductive surfaces of the objective.
Therefore, 97% of the heat developed in the heater goes directly into the objective.  This statement is backed up with thermographic images from a military grade quantitative IR camera. Images are on our web site.
This is a significant concern because any heat that does not go into the objective radiates outward and upward in the direction of the specimen.  
As an example, if you touch the heater band of a Bioptechs Objective heater you cannot tell the difference from its temperature and the rest of the objective.  
Try that with a Silicone blanket or ring heater and you will feel what I mean.
In an efficient system, it only requires between 1.3 to 1.7 watts of energy to warm an average objective from 22 to 37 degrees C.
Any system that uses more energy than that is not only wasteful but you have to consider where this excess energy is going!
In addition, not only do you need to warm the objective, you also have to overcome the constant heat-sinking effect of the nosepiece.  All the more reason for an efficient heat transfer.  Another reason that thermal transfer efficiency is important is that the control loop runs more efficiently because thermal corrections can take place on the fly instead of waiting a long time for the effect of energy changes to take effect due to thermal inertia.  

•  Accuracy - The Bioptechs Objective heater is controlled by a closed loop feedback based on the actual temperature of the objective.  This is accomplished by warming the objective about 3/4 of its diameter and measuring the heat that has been transferred to the objective in an adjacent location away from the heat transfer surface.   Therefore, the system is based on the temperature of the objective and not on the temperature of a simplistic heater ring!
The temperature of the heated ring is not what is important as long as it does not do damage.  
What you care about is the temperature at the specimen plane and that the objective is not harmed.  
Therefore, our operating setpoint is determined at the specimen plane of the objective.  
Other systems simply regulate the temperature of the heating collar with no regard to the temperature at the place that really matters, the specimen plane!
We do a thermal profile of objectives with the quantitative IR camera to know how they behave when heated.  

•  Safety- Bioptechs has been producing objective heaters for 18.5 years for all modes of microscopy.  We have found that even daily temperature cycling has never caused damage to an objective.  Our controllers, with their safety shutdown and alarm circuitry, warms the objective up over a 15 minute period of time so there is no thermal shock to the objective.  If you held an objective in your hand it would warm up faster than that!  As long as the Objective Heater is attached correctly to the objective, we have had no problems.  

I have seen warm air blowers, velcro attached heaters or blankets, and heated metal rings all of which have the afore mentioned issues.
I you feel comfortable trusting your objective to a silicone rubber heater held in place with velcro or a clamp on metal ring I can't help.

If you want to try one of our systems just call and we will arrange a free demo.  

Additional information:
http://www.bioptechs.com/Products/OBJ_HTR/obj_htr.html

Movie:
http://www.bioptechs.com/movies/product/ObjectiveHtrdvd06.mov

We have distributors all over the world and would be happy to serve you.
We are very detailed in identifying the correct Objective Heater for your objective.  
Therefore, we need to know the exact objective you want to control.  


Dan



On Mar 22, 2011, at 5:14 PM, Neil Kad wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I want to use an objective heater for my home-built TIRF. I have an Olympus
1.45NA objective and more temperature control would be nice.

What kind of objective heaters are used out there and is there anything I
need to watch out for?

Cheers

Neil

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]

[Xuejun Sun]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Thanks, Dan, but I like to emphasize this sentence:

"As long as the Objective Heater is attached correctly to the objective, we
have had no problems."

None of the objective heaters I used (Pecon through Zeiss we got and
Bioptechs) has any safe-guard mechanisms built-in, E.g if the temperature
sensor fails to read correctly, you might end up with a toasted lens or
heater. In the case of Pecon, one of the few we had, we had an instance that
temperature runs to the level of so hot that I could not hold it in my hands
because the wire of the temp. sensor broke inside (which one does not know
with the simple controller we disposed of). The Bioptech one, if it is not
attached properly (hard to monitor in a multi-user facility), you will smell
burning plastic soon.

My advice: get away from objective heater and get an scope enclosure if you
could afford one.

Regards,

Xuejun


Xuejun SUN, Ph.D.
Faculty Service Officer
Dept. Exp. Oncology
Cross Cancer Institute
11560  University Ave.
Edmonton Alberta, T6G1Z2

Phone  [phone] (office)
           [phone]/8458 (lab)
Fax:     [phone]
Preferred Email:  [hidden email]

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On
Behalf Of Dan Focht
Sent: Tuesday, March 22, 2011 5:06 PM
To: [hidden email]
Subject: Re: Objective Heaters Commercial response

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Neil

There are significant differences in the design and operation of Objective
Heaters.
I have studied this extensively and used the results of these studies to
develop and produce the Bioptechs Objective heater system.
Our system is not just a copy of an idea it is the first commercial,
patented, Objective Heater System.
Other companies have copied the idea of warming an objective but not the
technology behind it.
Here are a few of the differences between the Bioptechs and other companies
products.

In my opinion as an engineer, the Bioptechs Objective Heater System provides
the most efficient, accurate and safe means of objective temperature
control.

.  Most efficient  - heat is transferred to the barrel of the objective by
the highest efficiency conductive means by a thin film heater directly in
contact with the most thermally conductive surfaces of the objective.
Therefore, 97% of the heat developed in the heater goes directly into the
objective.  This statement is backed up with thermographic images from a
military grade quantitative IR camera. Images are on our web site.
This is a significant concern because any heat that does not go into the
objective radiates outward and upward in the direction of the specimen.
As an example, if you touch the heater band of a Bioptechs Objective heater
you cannot tell the difference from its temperature and the rest of the
objective.
Try that with a Silicone blanket or ring heater and you will feel what I
mean.
In an efficient system, it only requires between 1.3 to 1.7 watts of energy
to warm an average objective from 22 to 37 degrees C.
Any system that uses more energy than that is not only wasteful but you have
to consider where this excess energy is going!
In addition, not only do you need to warm the objective, you also have to
overcome the constant heat-sinking effect of the nosepiece.  All the more
reason for an efficient heat transfer.  Another reason that thermal transfer
efficiency is important is that the control loop runs more efficiently
because thermal corrections can take place on the fly instead of waiting a
long time for the effect of energy changes to take effect due to thermal
inertia.

.  Accuracy - The Bioptechs Objective heater is controlled by a closed loop
feedback based on the actual temperature of the objective.  This is
accomplished by warming the objective about 3/4 of its diameter and
measuring the heat that has been transferred to the objective in an adjacent
location away from the heat transfer surface.   Therefore, the system is
based on the temperature of the objective and not on the temperature of a
simplistic heater ring!
The temperature of the heated ring is not what is important as long as it
does not do damage.
What you care about is the temperature at the specimen plane and that the
objective is not harmed.
Therefore, our operating setpoint is determined at the specimen plane of the
objective.
Other systems simply regulate the temperature of the heating collar with no
regard to the temperature at the place that really matters, the specimen
plane!
We do a thermal profile of objectives with the quantitative IR camera to
know how they behave when heated.

.  Safety- Bioptechs has been producing objective heaters for 18.5 years for
all modes of microscopy.  We have found that even daily temperature cycling
has never caused damage to an objective.  Our controllers, with their safety
shutdown and alarm circuitry, warms the objective up over a 15 minute period
of time so there is no thermal shock to the objective.  If you held an
objective in your hand it would warm up faster than that!  As long as the
Objective Heater is attached correctly to the objective, we have had no
problems.

I have seen warm air blowers, velcro attached heaters or blankets, and
heated metal rings all of which have the afore mentioned issues.
I you feel comfortable trusting your objective to a silicone rubber heater
held in place with velcro or a clamp on metal ring I can't help.

If you want to try one of our systems just call and we will arrange a free
demo.

Additional information:
http://www.bioptechs.com/Products/OBJ_HTR/obj_htr.html

Movie:
http://www.bioptechs.com/movies/product/ObjectiveHtrdvd06.mov

We have distributors all over the world and would be happy to serve you.
We are very detailed in identifying the correct Objective Heater for your
objective.
Therefore, we need to know the exact objective you want to control.


Dan



On Mar 22, 2011, at 5:14 PM, Neil Kad wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I want to use an objective heater for my home-built TIRF. I have an Olympus
1.45NA objective and more temperature control would be nice.

What kind of objective heaters are used out there and is there anything I
need to watch out for?

Cheers

Neil

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]


This message and any attached documents are only for the use of the intended recipient(s), are confidential and may contain privileged information. Any unauthorized review, use, retransmission, or other disclosure is strictly prohibited. If you have received this message in error, please notify the sender immediately, and then delete the original message. Thank you.

[Dan Focht]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Xuejun

Thank you for pointing out the overheating issue with Pe-Con.
I did not know theirs would do that!  

There is a safety circuit in the Bioptechs objective heater that continuously looks for the temperature to drop out of a 0.9 degree error window.
When and if this happens it is due to an improperly attached objective.  
When the temperature sensor goes cool beyond the error window, after having warmed the objective, all power to the heater is shut off and an annoying alarm goes off on the controller.
This is done to safeguard the objective.  
The only time the heater-band overheats is if someone turns the controller on with the heater plugged in to the controller but NOT attached to an objective!
The system needs something to heat to complete the control loop.  
We cannot help it if somebody does not attach it properly.  
Our newest Objective Heater now has a secondary retaining strap to provide a secure attachment to the objective.
The power cord is detachable so you can have several heaters on the nosepiece, rotate the nosepiece and just plug in the one you want to use when you want to use it.
Like I said other companies have copied the idea of warming an objective but not the technology.

If you have a damaged Objective Heater, call for a RMA number to send it in for repair.  

Dan



On Mar 23, 2011, at 2:28 PM, Xuejun SUN wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Thanks, Dan, but I like to emphasize this sentence:

"As long as the Objective Heater is attached correctly to the objective, we
have had no problems."

None of the objective heaters I used (Pecon through Zeiss we got and
Bioptechs) has any safe-guard mechanisms built-in, E.g if the temperature
sensor fails to read correctly, you might end up with a toasted lens or
heater. In the case of Pecon, one of the few we had, we had an instance that
temperature runs to the level of so hot that I could not hold it in my hands
because the wire of the temp. sensor broke inside (which one does not know
with the simple controller we disposed of). The Bioptech one, if it is not
attached properly (hard to monitor in a multi-user facility), you will smell
burning plastic soon.

My advice: get away from objective heater and get an scope enclosure if you
could afford one.

Regards,

Xuejun


Xuejun SUN, Ph.D.
Faculty Service Officer
Dept. Exp. Oncology
Cross Cancer Institute
11560  University Ave.
Edmonton Alberta, T6G1Z2

Phone  [phone] (office)
          [phone]/8458 (lab)
Fax:     [phone]
Preferred Email:  [hidden email]

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On
Behalf Of Dan Focht
Sent: Tuesday, March 22, 2011 5:06 PM
To: [hidden email]
Subject: Re: Objective Heaters Commercial response

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Neil

There are significant differences in the design and operation of Objective
Heaters.
I have studied this extensively and used the results of these studies to
develop and produce the Bioptechs Objective heater system.
Our system is not just a copy of an idea it is the first commercial,
patented, Objective Heater System.
Other companies have copied the idea of warming an objective but not the
technology behind it.
Here are a few of the differences between the Bioptechs and other companies
products.

In my opinion as an engineer, the Bioptechs Objective Heater System provides
the most efficient, accurate and safe means of objective temperature
control.

.  Most efficient  - heat is transferred to the barrel of the objective by
the highest efficiency conductive means by a thin film heater directly in
contact with the most thermally conductive surfaces of the objective.
Therefore, 97% of the heat developed in the heater goes directly into the
objective.  This statement is backed up with thermographic images from a
military grade quantitative IR camera. Images are on our web site.
This is a significant concern because any heat that does not go into the
objective radiates outward and upward in the direction of the specimen.
As an example, if you touch the heater band of a Bioptechs Objective heater
you cannot tell the difference from its temperature and the rest of the
objective.
Try that with a Silicone blanket or ring heater and you will feel what I
mean.
In an efficient system, it only requires between 1.3 to 1.7 watts of energy
to warm an average objective from 22 to 37 degrees C.
Any system that uses more energy than that is not only wasteful but you have
to consider where this excess energy is going!
In addition, not only do you need to warm the objective, you also have to
overcome the constant heat-sinking effect of the nosepiece.  All the more
reason for an efficient heat transfer.  Another reason that thermal transfer
efficiency is important is that the control loop runs more efficiently
because thermal corrections can take place on the fly instead of waiting a
long time for the effect of energy changes to take effect due to thermal
inertia.

.  Accuracy - The Bioptechs Objective heater is controlled by a closed loop
feedback based on the actual temperature of the objective.  This is
accomplished by warming the objective about 3/4 of its diameter and
measuring the heat that has been transferred to the objective in an adjacent
location away from the heat transfer surface.   Therefore, the system is
based on the temperature of the objective and not on the temperature of a
simplistic heater ring!
The temperature of the heated ring is not what is important as long as it
does not do damage.
What you care about is the temperature at the specimen plane and that the
objective is not harmed.
Therefore, our operating setpoint is determined at the specimen plane of the
objective.
Other systems simply regulate the temperature of the heating collar with no
regard to the temperature at the place that really matters, the specimen
plane!
We do a thermal profile of objectives with the quantitative IR camera to
know how they behave when heated.

.  Safety- Bioptechs has been producing objective heaters for 18.5 years for
all modes of microscopy.  We have found that even daily temperature cycling
has never caused damage to an objective.  Our controllers, with their safety
shutdown and alarm circuitry, warms the objective up over a 15 minute period
of time so there is no thermal shock to the objective.  If you held an
objective in your hand it would warm up faster than that!  As long as the
Objective Heater is attached correctly to the objective, we have had no
problems.

I have seen warm air blowers, velcro attached heaters or blankets, and
heated metal rings all of which have the afore mentioned issues.
I you feel comfortable trusting your objective to a silicone rubber heater
held in place with velcro or a clamp on metal ring I can't help.

If you want to try one of our systems just call and we will arrange a free
demo.

Additional information:
http://www.bioptechs.com/Products/OBJ_HTR/obj_htr.html

Movie:
http://www.bioptechs.com/movies/product/ObjectiveHtrdvd06.mov

We have distributors all over the world and would be happy to serve you.
We are very detailed in identifying the correct Objective Heater for your
objective.
Therefore, we need to know the exact objective you want to control.


Dan



On Mar 22, 2011, at 5:14 PM, Neil Kad wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I want to use an objective heater for my home-built TIRF. I have an Olympus
1.45NA objective and more temperature control would be nice.

What kind of objective heaters are used out there and is there anything I
need to watch out for?

Cheers

Neil

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]


This message and any attached documents are only for the use of the intended recipient(s), are confidential and may contain privileged information. Any unauthorized review, use, retransmission, or other disclosure is strictly prohibited. If you have received this message in error, please notify the sender immediately, and then delete the original message. Thank you.

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]

[Guy Cox-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Surely this situation is easy to test for.  The temperature increase for
a given heater current will be hugely higher if the heat-sink
(objective) is not in good contact.  It shouldn't be difficult to
implement a check for this in the controller circuitry.  

 

Xuejun's other point was sensor failure - and again surely the circuitry
should check for this.  Likely failure modes are open circuit or short
circuit - both easily testable conditions, at least if the sensor is a
thermistor or other resistive device.  

 

 
Guy

 

Sponsor my next half-marathon on May 15th

There's a special reason - find it out at

http://www.everydayhero.com.au/Guy_Cox_4846
<http://www.everydayhero.com.au/Guy_Cox_4846>

______________________________________________

Associate Professor Guy Cox, MA, DPhil(Oxon)

Australian Centre for Microscopy & Microanalysis,

Madsen Building F09, University of Sydney, NSW 2006

 

Phone [phone]     Fax [phone]

             Mobile [phone]

______________________________________________

      http://www.guycox.net <http://www.guycox.net/>

 

From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Dan Focht
Sent: Thursday, 24 March 2011 6:46 AM
To: [hidden email]
Subject: Re: Objective Heaters Commercial response

 

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Xuejun

Thank you for pointing out the overheating issue with Pe-Con.
I did not know theirs would do that!

There is a safety circuit in the Bioptechs objective heater that
continuously looks for the temperature to drop out of a 0.9 degree error
window.
When and if this happens it is due to an improperly attached objective.
When the temperature sensor goes cool beyond the error window, after
having warmed the objective, all power to the heater is shut off and an
annoying alarm goes off on the controller.
This is done to safeguard the objective.
The only time the heater-band overheats is if someone turns the
controller on with the heater plugged in to the controller but NOT
attached to an objective!
The system needs something to heat to complete the control loop.
We cannot help it if somebody does not attach it properly.
Our newest Objective Heater now has a secondary retaining strap to
provide a secure attachment to the objective.
The power cord is detachable so you can have several heaters on the
nosepiece, rotate the nosepiece and just plug in the one you want to use
when you want to use it.
Like I said other companies have copied the idea of warming an objective
but not the technology.

If you have a damaged Objective Heater, call for a RMA number to send it
in for repair.

Dan



On Mar 23, 2011, at 2:28 PM, Xuejun SUN wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Thanks, Dan, but I like to emphasize this sentence:

"As long as the Objective Heater is attached correctly to the objective,
we
have had no problems."

None of the objective heaters I used (Pecon through Zeiss we got and
Bioptechs) has any safe-guard mechanisms built-in, E.g if the
temperature
sensor fails to read correctly, you might end up with a toasted lens or
heater. In the case of Pecon, one of the few we had, we had an instance
that
temperature runs to the level of so hot that I could not hold it in my
hands
because the wire of the temp. sensor broke inside (which one does not
know
with the simple controller we disposed of). The Bioptech one, if it is
not
attached properly (hard to monitor in a multi-user facility), you will
smell
burning plastic soon.

My advice: get away from objective heater and get an scope enclosure if
you
could afford one.

Regards,

Xuejun


Xuejun SUN, Ph.D.
Faculty Service Officer
Dept. Exp. Oncology
Cross Cancer Institute
11560  University Ave.
Edmonton Alberta, T6G1Z2

Phone  [phone] (office)
          [phone]/8458 (lab)
Fax:     [phone]
Preferred Email:  [hidden email]

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On
Behalf Of Dan Focht
Sent: Tuesday, March 22, 2011 5:06 PM
To: [hidden email]
Subject: Re: Objective Heaters Commercial response

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Neil

There are significant differences in the design and operation of
Objective
Heaters.
I have studied this extensively and used the results of these studies to
develop and produce the Bioptechs Objective heater system.
Our system is not just a copy of an idea it is the first commercial,
patented, Objective Heater System.
Other companies have copied the idea of warming an objective but not the
technology behind it.
Here are a few of the differences between the Bioptechs and other
companies
products.

In my opinion as an engineer, the Bioptechs Objective Heater System
provides
the most efficient, accurate and safe means of objective temperature
control.

.  Most efficient  - heat is transferred to the barrel of the objective
by
the highest efficiency conductive means by a thin film heater directly
in
contact with the most thermally conductive surfaces of the objective.
Therefore, 97% of the heat developed in the heater goes directly into
the
objective.  This statement is backed up with thermographic images from a
military grade quantitative IR camera. Images are on our web site.
This is a significant concern because any heat that does not go into the
objective radiates outward and upward in the direction of the specimen.
As an example, if you touch the heater band of a Bioptechs Objective
heater
you cannot tell the difference from its temperature and the rest of the
objective.
Try that with a Silicone blanket or ring heater and you will feel what I
mean.
In an efficient system, it only requires between 1.3 to 1.7 watts of
energy
to warm an average objective from 22 to 37 degrees C.
Any system that uses more energy than that is not only wasteful but you
have
to consider where this excess energy is going!
In addition, not only do you need to warm the objective, you also have
to
overcome the constant heat-sinking effect of the nosepiece.  All the
more
reason for an efficient heat transfer.  Another reason that thermal
transfer
efficiency is important is that the control loop runs more efficiently
because thermal corrections can take place on the fly instead of waiting
a
long time for the effect of energy changes to take effect due to thermal
inertia.

.  Accuracy - The Bioptechs Objective heater is controlled by a closed
loop
feedback based on the actual temperature of the objective.  This is
accomplished by warming the objective about 3/4 of its diameter and
measuring the heat that has been transferred to the objective in an
adjacent
location away from the heat transfer surface.   Therefore, the system is
based on the temperature of the objective and not on the temperature of
a
simplistic heater ring!
The temperature of the heated ring is not what is important as long as
it
does not do damage.
What you care about is the temperature at the specimen plane and that
the
objective is not harmed.
Therefore, our operating setpoint is determined at the specimen plane of
the
objective.
Other systems simply regulate the temperature of the heating collar with
no
regard to the temperature at the place that really matters, the specimen
plane!
We do a thermal profile of objectives with the quantitative IR camera to
know how they behave when heated.

.  Safety- Bioptechs has been producing objective heaters for 18.5 years
for
all modes of microscopy.  We have found that even daily temperature
cycling
has never caused damage to an objective.  Our controllers, with their
safety
shutdown and alarm circuitry, warms the objective up over a 15 minute
period
of time so there is no thermal shock to the objective.  If you held an
objective in your hand it would warm up faster than that!  As long as
the
Objective Heater is attached correctly to the objective, we have had no
problems.

I have seen warm air blowers, velcro attached heaters or blankets, and
heated metal rings all of which have the afore mentioned issues.
I you feel comfortable trusting your objective to a silicone rubber
heater
held in place with velcro or a clamp on metal ring I can't help.

If you want to try one of our systems just call and we will arrange a
free
demo.

Additional information:
http://www.bioptechs.com/Products/OBJ_HTR/obj_htr.html

Movie:
http://www.bioptechs.com/movies/product/ObjectiveHtrdvd06.mov

We have distributors all over the world and would be happy to serve you.
We are very detailed in identifying the correct Objective Heater for
your
objective.
Therefore, we need to know the exact objective you want to control.


Dan



On Mar 22, 2011, at 5:14 PM, Neil Kad wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I want to use an objective heater for my home-built TIRF. I have an
Olympus
1.45NA objective and more temperature control would be nice.

What kind of objective heaters are used out there and is there anything
I
need to watch out for?

Cheers

Neil

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]


This message and any attached documents are only for the use of the
intended recipient(s), are confidential and may contain privileged
information. Any unauthorized review, use, retransmission, or other
disclosure is strictly prohibited. If you have received this message in
error, please notify the sender immediately, and then delete the
original message. Thank you.

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]

________________________________

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1204 / Virus Database: 1498/3523 - Release Date: 03/22/11

[Jeremy Adler-4]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

A problem with objective heaters is the time taken to reach thermal  
equilibrium.
For high resolution imaging thermal stability is critical.

  The problem with feedback control is the location of the sensor -  
ideally inside the imaging chamber.
Depending on where the sensor is located there may be an unknown  
offset between the sensor and the cell or tissue. This is why i prefer  
to hear the whole microscope - all areas within the enclosure and  
distant from the the edges must eventually reach the feedback  
controlled temperature.

Does anyone know of a temperature sensitive fluorophore ? be great for  
discovering the actual temperature

J. Adler and S.N. Pagakis (2003)
Reducing Image Distortions Due To Temperature Related Microscope Stage Drift
J. Microscopy, 210, 131-137.





Quoting Neil Kad <[hidden email]>:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> I want to use an objective heater for my home-built TIRF. I have an Olympus
> 1.45NA objective and more temperature control would be nice.
>
> What kind of objective heaters are used out there and is there anything I
> need to watch out for?
>
> Cheers
>
> Neil
>

Jeremy Adler
Genetics & Pathology
Rudbeckslaboratoriet
Daghammersköljdsväg 20
751 85 Uppsala
Sweden

0046 (0)18 471 4607

[Dan Focht]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Jeremy

I agree that the important issue is the temperature at the specimen  
plane.
We recognize that all objectives have a different thermal profile.
Therefore, we know you can't just set the control for 37 degrees and  
be done with it.

That is why Bioptechs Objective Heaters come with a NIST traceable  
Thermistor that is to be placed on the lens, in a drop of oil, to  
measure the temperature at the specimen plane.  Having that  
information allows the user to adjust the setpoint of the controller  
for accuracy.

I would never put the temperature sensor that regulates the objective  
inside the imaging chamber.
The role of the objective heater is NOT to warm the specimen, so the  
feed-back should not be based on any other thermal influence than the  
objective!  If you based the control of the Objective Heater on the  
temperature in the specimen container, you will get oscillations due  
to all the factors that affect the specimen such as surface  
evaporation, perfusion, entropy, etc.
The role of the Objective Heater is to prevent the objective from  
being a heat-sink to the specimen.

It is the combination of a temperature regulated specimen in fluid  
contact with an objective that does not remove heat from the specimen  
that works best to provide a stable balance.


Dan


On Mar 24, 2011, at 6:17 AM, Jeremy Adler wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> A problem with objective heaters is the time taken to reach thermal  
> equilibrium.
> For high resolution imaging thermal stability is critical.
>
>  The problem with feedback control is the location of the sensor -  
> ideally inside the imaging chamber.
> Depending on where the sensor is located there may be an unknown  
> offset between the sensor and the cell or tissue. This is why i  
> prefer to hear the whole microscope - all areas within the  
> enclosure and distant from the the edges must eventually reach the  
> feedback controlled temperature.
>
> Does anyone know of a temperature sensitive fluorophore ? be great  
> for discovering the actual temperature
>
> J. Adler and S.N. Pagakis (2003)
> Reducing Image Distortions Due To Temperature Related Microscope  
> Stage Drift
> J. Microscopy, 210, 131-137.
>
>
>
>
>
> Quoting Neil Kad <[hidden email]>:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> I want to use an objective heater for my home-built TIRF. I have  
>> an Olympus
>> 1.45NA objective and more temperature control would be nice.
>>
>> What kind of objective heaters are used out there and is there  
>> anything I
>> need to watch out for?
>>
>> Cheers
>>
>> Neil
>>
>
>
>
> Jeremy Adler
> Genetics & Pathology
> Rudbeckslaboratoriet
> Daghammersköljdsväg 20
> 751 85 Uppsala
> Sweden
>
> 0046 (0)18 471 4607

Dan Focht
[hidden email]
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
Direct 724-282-7145
Fax [phone]
Toll Free 877 LIVE-CELL - (548-3235)

[Stephen Cody-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear List,

For the sake of completeness I think the Warner objective heater should be
mentioned. This differs slightly from those discussed so far, in that the
heating collar is not directly coupled to the lens. There is instead a
deliberate air space between the heating collar and lens. Presumably this
adds a little capacitance to the heat transfer process. It may reduce some
of the tendency for temperature cycling. It also is their way of simplifying
the build to suit different shapes and sizes of lens, although they sell
small, medium and large versions. It should avoid problems with badly
attached heat sensors. Presumably the heat sensor is on the collar itself or
in the airspace, this would result in a slow, but conservative heating
mechanism.

I myself use heated chambers that enclose the stage and objectives, with a
sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.

See link: http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
Warmers


Caveats: I haven't used any commercial objective heaters,
No commercial affiliation with any objective heater companies.

--
Stephen H. Cody

[Dan Focht]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Stephan


I agree that boxing the whole microscope or stage and objective area is a solution.  
However, for those who don't want to box the scope for a variety of reasons. The following applies.

From the Warner web page:
"Heat generated by the isolated collar is not directly communicated to the objective but is instead distributed around the objective via a conducting sleeve."

When I read this my first impression is,  "What?, they intentionally isolate the heat source from the objective!"
That means they rely on radiation, which goes in all directions (not just toward the objective)  and a little conductivity from air, another inefficient heat transfer means.  
Thermal conductivity of air 0.024 W/(m.oC).  Thermal conductivity of brass 109 W/(m.oC). In terms of thermal transfer efficiency, there is no comparison, not even in the ball park!

Again from the Warner site:
"The conducting sleeve warms the surrounding air, which in turn gently warms the objective. This approach allows the apparatus to take full advantage of the thermal characteristics of the surrounding air. The warmer achieves its task without directly contacting or exposing the objective to significant stresses associated with temperature gradients."

I look at it this way.  
I know the thermal characteristics of air, and it is poor.  
You have an objective screwed into a nosepiece that you want to warm to 37 degrees C.  
The objective is about 150 to 225 grams of brass, glass and airspace not to mention the mass of the nosepiece.
I mention the mass of the nosepiece because it acts as a heat sink requiring constant compensation thus  more energy to maintain constant temperature.
 
1. Do you think you can accurately transfer enough heat to warm the objective with the additional thermal drain of the nosepiece from an air-spaced heat source without excessive heat being produced in the vicinity of the objective where it radiates outward and upward?  
 
2. Do you think you can maintain a constant accurate temperature when you have to wait for the heat to be transferred through air to get to the objective without inducing excessive temperature cycling?  
   It is the inefficiency of heat transfer that causes cycling.  We thermally profile objectives to be certain that the surface that heat is transferred from or to is as efficient as possible to minimize

3. If your thermal transfer efficiency is as good as it should be, the heat source only has to be only a couple of percent higher than the temperature of the objective.
Given the thermal inefficiency of air, I never even entertained using air to conduct heat to an objective.  
However, if someone out there has one of these and would lend it to me for a couple of days, I would be glad to do a thermal propagation time-lapse of it with our military grade quantitative IR camera.
It would be in movie form and I would make it available to anyone that wants it.  This is a costly thing to do but the data would be worth it.  

Note, All four major microscope manufacturers have issued a letter to me that the objectives can withstand up to 50 degrees C.  I thought that was generous but understandable.  
The temperature of the objective can get a lot higher than 37 degrees while it is sitting in the delivery truck waiting to be delivered.

Note, I refrained from naming other companies in my first reply.  Now that the door is open, I guess ,SWAG, I can walk in.


Dan

> From: Stephen Cody <[hidden email]>
> Date: March 27, 2011 10:30:22 PM EDT
> To: [hidden email]
> Subject: Re: Objective Heaters
> Reply-To: Confocal Microscopy List <[hidden email]>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear List,
>
> For the sake of completeness I think the Warner objective heater should be
> mentioned. This differs slightly from those discussed so far, in that the
> heating collar is not directly coupled to the lens. There is instead a
> deliberate air space between the heating collar and lens. Presumably this
> adds a little capacitance to the heat transfer process. It may reduce some
> of the tendency for temperature cycling. It also is their way of simplifying
> the build to suit different shapes and sizes of lens, although they sell
> small, medium and large versions. It should avoid problems with badly
> attached heat sensors. Presumably the heat sensor is on the collar itself or
> in the airspace, this would result in a slow, but conservative heating
> mechanism.
>
> I myself use heated chambers that enclose the stage and objectives, with a
> sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.
>
> See link: http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
> Warmers
>
>
> Caveats: I haven't used any commercial objective heaters,
> No commercial affiliation with any objective heater companies.
>
> --
> Stephen H. Cody

Dan Focht
[hidden email]
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
Direct 724-282-7145
Fax [phone]
Toll Free 877 LIVE-CELL - (548-3235)

[Clements, Ian]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear Listmembers

We are currently recruiting for an experienced Bio Engineer/Service Engineer to join our DeltaVision OMX super-resolution microscope support team. The position of Bio Engineer is part of the Life Sciences Service Team. Under limited supervision, provides installation, training and advanced technical and applications support for API end customers and distributors.  For more details follow the link below.

This is the direct link to the job profile.
https://www.recruitingcenter.net/Clients/appliedprecision/PublicJobs/controller.cfm?jbaction=JobProfile&job_id=10033


If you experience problems using the link, copy and paste the entire URL / website address below into your browser's address bar.

https://www.recruitingcenter.net/Clients/appliedprecision/PublicJobs/controller.cfm?jbaction=JobProfile&job_id=10033

You can also access this and other open positions through our website at http://www.appliedprecision.com/current-openings.asp


Ian Clements
Product Manager - DeltaVision OMX Systems


This email message, together with any attachments, is for the sole use of the intended recipient(s) and is the confidential information of Applied Precision Inc. If you are not the intended recipient, your review, use, disclosure, copying or dissemination of this email message or its attachments, or the information contained therein, is strictly prohibited. If you are not the intended recipient or if you think this email was sent to you in error, please notify the sender by reply email and delete this message and its attachments, as well as all copies, from your system.

[Guy Cox-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Maybe I should point out to Dan that it was Steve Cody, not Wamer, who
mentioned their product.  Both Steve and I are interested in the whole
range of these products simply because we cater for a wide range of
users, we teach courses for all comers, and (in my case at least) write
books for the whole gamut of life-science researchers.

 

So I would still be interested to get a response from Dan to my query -
why is it that his controller cannot detect that the heater is detached
from the lens?  It should be simple.

 

As to the temperature a lens can handle, I am sure 50C is not a problem
but it is vital to heat it slowly - there is a lot of glass there and it
is a very poor conductor of heat.  (Brass isn't that good but it's a lot
better than glass).  I suspect a body at 50C with optics at 20C would be
disastrous.

 

 
Guy

 

Sponsor my next half-marathon on May 15th

There's a special reason - find it out at

http://www.everydayhero.com.au/Guy_Cox_4846
<http://www.everydayhero.com.au/Guy_Cox_4846>

______________________________________________

Associate Professor Guy Cox, MA, DPhil(Oxon)

Australian Centre for Microscopy & Microanalysis,

Madsen Building F09, University of Sydney, NSW 2006

 

Phone [phone]     Fax [phone]

             Mobile [phone]

______________________________________________

      http://www.guycox.net <http://www.guycox.net/>

 

From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Dan Focht
Sent: Tuesday, 29 March 2011 7:25 AM
To: [hidden email]
Subject: Re: Objective Heaters

 

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Stephan


I agree that boxing the whole microscope or stage and objective area is
a solution.
However, for those who don't want to box the scope for a variety of
reasons. The following applies.

From the Warner web page:
"Heat generated by the isolated collar is not directly communicated to
the objective but is instead distributed around the objective via a
conducting sleeve."

When I read this my first impression is,  "What?, they intentionally
isolate the heat source from the objective!"
That means they rely on radiation, which goes in all directions (not
just toward the objective)  and a little conductivity from air, another
inefficient heat transfer means.
Thermal conductivity of air 0.024 W/(m.oC).  Thermal conductivity of
brass 109 W/(m.oC). In terms of thermal transfer efficiency, there is no
comparison, not even in the ball park!

Again from the Warner site:
"The conducting sleeve warms the surrounding air, which in turn gently
warms the objective. This approach allows the apparatus to take full
advantage of the thermal characteristics of the surrounding air. The
warmer achieves its task without directly contacting or exposing the
objective to significant stresses associated with temperature
gradients."

I look at it this way.
I know the thermal characteristics of air, and it is poor.
You have an objective screwed into a nosepiece that you want to warm to
37 degrees C.
The objective is about 150 to 225 grams of brass, glass and airspace not
to mention the mass of the nosepiece.
I mention the mass of the nosepiece because it acts as a heat sink
requiring constant compensation thus  more energy to maintain constant
temperature.

1. Do you think you can accurately transfer enough heat to warm the
objective with the additional thermal drain of the nosepiece from an
air-spaced heat source without excessive heat being produced in the
vicinity of the objective where it radiates outward and upward?

2. Do you think you can maintain a constant accurate temperature when
you have to wait for the heat to be transferred through air to get to
the objective without inducing excessive temperature cycling?  
   It is the inefficiency of heat transfer that causes cycling.  We
thermally profile objectives to be certain that the surface that heat is
transferred from or to is as efficient as possible to minimize

3. If your thermal transfer efficiency is as good as it should be, the
heat source only has to be only a couple of percent higher than the
temperature of the objective.
Given the thermal inefficiency of air, I never even entertained using
air to conduct heat to an objective.
However, if someone out there has one of these and would lend it to me
for a couple of days, I would be glad to do a thermal propagation
time-lapse of it with our military grade quantitative IR camera.
It would be in movie form and I would make it available to anyone that
wants it.  This is a costly thing to do but the data would be worth it.

Note, All four major microscope manufacturers have issued a letter to me
that the objectives can withstand up to 50 degrees C.  I thought that
was generous but understandable.
The temperature of the objective can get a lot higher than 37 degrees
while it is sitting in the delivery truck waiting to be delivered.

Note, I refrained from naming other companies in my first reply.  Now
that the door is open, I guess ,SWAG, I can walk in.


Dan

> From: Stephen Cody <[hidden email]>
> Date: March 27, 2011 10:30:22 PM EDT
> To: [hidden email]
> Subject: Re: Objective Heaters
> Reply-To: Confocal Microscopy List <[hidden email]>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear List,
>
> For the sake of completeness I think the Warner objective heater

should be
> mentioned. This differs slightly from those discussed so far, in that
the
> heating collar is not directly coupled to the lens. There is instead a
> deliberate air space between the heating collar and lens. Presumably
this
> adds a little capacitance to the heat transfer process. It may reduce
some
> of the tendency for temperature cycling. It also is their way of
simplifying
> the build to suit different shapes and sizes of lens, although they
sell
> small, medium and large versions. It should avoid problems with badly
> attached heat sensors. Presumably the heat sensor is on the collar
itself or
> in the airspace, this would result in a slow, but conservative heating
> mechanism.
>
> I myself use heated chambers that enclose the stage and objectives,
with a
> sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.
>
> See link:
http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
> Warmers
>
>
> Caveats: I haven't used any commercial objective heaters,
> No commercial affiliation with any objective heater companies.
>
> --
> Stephen H. Cody

Dan Focht
[hidden email]
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
Direct 724-282-7145
Fax [phone]
Toll Free 877 LIVE-CELL - (548-3235)

________________________________

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1204 / Virus Database: 1498/3534 - Release Date: 03/27/11

[James Pawley]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Maybe I should point out to Dan that it was Steve Cody, not Wamer, who
>mentioned their product.  Both Steve and I are interested in the whole
>range of these products simply because we cater for a wide range of
>users, we teach courses for all comers, and (in my case at least) write
>books for the whole gamut of life-science researchers.
>
>
>
>So I would still be interested to get a response from Dan to my query -
>why is it that his controller cannot detect that the heater is detached
>from the lens?  It should be simple.
>
>
>
>As to the temperature a lens can handle, I am sure 50C is not a problem
>but it is vital to heat it slowly - there is a lot of glass there and it
>is a very poor conductor of heat.  (Brass isn't that good but it's a lot
>better than glass).  I suspect a body at 50C with optics at 20C would be
>disastrous.
>
>
>
>
>Guy

Hi Guy and Dan,

I don't have any experience myself but thought that it might be worth
noting that in Chapter 11 (on PSF), Rimas Juskaitis mentions that
when he cycled one lens from RT to 37 deg and back the process
changed the PSF of the lens by a small but detectable amount. Of
course, this wasn't the purpose of the experiment and it is possible
that the lens (or the oil) had not yet regained temperature
equilibrium etc.

However, the change impressed him enough that he mentioned it.

So I am not sure I would want to go to 50 deg. Maybe it might work in
a Pol lens where the lens elements are supposed to be held in such a
way that they are not strained by forces from the mount. I don't know
how they do this but I assume that it means a somewhat more gentle
connection between the brass and glass components. If this is so,
then differences in expansion coefficient between the glass and the
brass may be less likely to distort the shape of the optical surfaces.

Best,

Jim P.

***************************************************************************
Prof. James B. Pawley,                          Ph.
608-238-3953                        
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver Canada
Info: http://www.3dcourse.ubc.ca/            Applications due by March 15, 2011
               "If it ain't diffraction, it must be statistics." Anon.

>
>
>Sponsor my next half-marathon on May 15th
>
>There's a special reason - find it out at
>
>http://www.everydayhero.com.au/Guy_Cox_4846
><http://www.everydayhero.com.au/Guy_Cox_4846>
>
>______________________________________________
>
>Associate Professor Guy Cox, MA, DPhil(Oxon)
>
>Australian Centre for Microscopy & Microanalysis,
>
>Madsen Building F09, University of Sydney, NSW 2006
>
>
>
>Phone [phone]     Fax [phone]
>
>              Mobile [phone]
>
>______________________________________________
>
>       http://www.guycox.net <http://www.guycox.net/>
>
>
>
>From: Confocal Microscopy List [mailto:[hidden email]]
>On Behalf Of Dan Focht
>Sent: Tuesday, 29 March 2011 7:25 AM
>To: [hidden email]
>Subject: Re: Objective Heaters
>
>
>
>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Stephan
>
>
>I agree that boxing the whole microscope or stage and objective area is
>a solution.
>However, for those who don't want to box the scope for a variety of
>reasons. The following applies.
>
>From the Warner web page:
>"Heat generated by the isolated collar is not directly communicated to
>the objective but is instead distributed around the objective via a
>conducting sleeve."
>
>When I read this my first impression is,  "What?, they intentionally
>isolate the heat source from the objective!"
>That means they rely on radiation, which goes in all directions (not
>just toward the objective)  and a little conductivity from air, another
>inefficient heat transfer means.
>Thermal conductivity of air 0.024 W/(m.oC).  Thermal conductivity of
>brass 109 W/(m.oC). In terms of thermal transfer efficiency, there is no
>comparison, not even in the ball park!
>
>Again from the Warner site:
>"The conducting sleeve warms the surrounding air, which in turn gently
>warms the objective. This approach allows the apparatus to take full
>advantage of the thermal characteristics of the surrounding air. The
>warmer achieves its task without directly contacting or exposing the
>objective to significant stresses associated with temperature
>gradients."
>
>I look at it this way.
>I know the thermal characteristics of air, and it is poor.
>You have an objective screwed into a nosepiece that you want to warm to
>37 degrees C.
>The objective is about 150 to 225 grams of brass, glass and airspace not
>to mention the mass of the nosepiece.
>I mention the mass of the nosepiece because it acts as a heat sink
>requiring constant compensation thus  more energy to maintain constant
>temperature.
>
>1. Do you think you can accurately transfer enough heat to warm the
>objective with the additional thermal drain of the nosepiece from an
>air-spaced heat source without excessive heat being produced in the
>vicinity of the objective where it radiates outward and upward?
>
>2. Do you think you can maintain a constant accurate temperature when
>you have to wait for the heat to be transferred through air to get to
>the objective without inducing excessive temperature cycling?
>    It is the inefficiency of heat transfer that causes cycling.  We
>thermally profile objectives to be certain that the surface that heat is
>transferred from or to is as efficient as possible to minimize
>
>3. If your thermal transfer efficiency is as good as it should be, the
>heat source only has to be only a couple of percent higher than the
>temperature of the objective.
>Given the thermal inefficiency of air, I never even entertained using
>air to conduct heat to an objective.
>However, if someone out there has one of these and would lend it to me
>for a couple of days, I would be glad to do a thermal propagation
>time-lapse of it with our military grade quantitative IR camera.
>It would be in movie form and I would make it available to anyone that
>wants it.  This is a costly thing to do but the data would be worth it.
>
>Note, All four major microscope manufacturers have issued a letter to me
>that the objectives can withstand up to 50 degrees C.  I thought that
>was generous but understandable.
>The temperature of the objective can get a lot higher than 37 degrees
>while it is sitting in the delivery truck waiting to be delivered.
>
>Note, I refrained from naming other companies in my first reply.  Now
>that the door is open, I guess ,SWAG, I can walk in.
>
>
>Dan
>
>
>
>>  From: Stephen Cody <[hidden email]>
>>  Date: March 27, 2011 10:30:22 PM EDT
>>  To: [hidden email]
>>  Subject: Re: Objective Heaters
>>  Reply-To: Confocal Microscopy List <[hidden email]>
>>
>>  *****
>>  To join, leave or search the confocal microscopy listserv, go to:
>>  http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>  *****
>>
>>  Dear List,
>>
>>  For the sake of completeness I think the Warner objective heater
>should be
>>  mentioned. This differs slightly from those discussed so far, in that
>the
>>  heating collar is not directly coupled to the lens. There is instead a
>>  deliberate air space between the heating collar and lens. Presumably
>this
>>  adds a little capacitance to the heat transfer process. It may reduce
>some
>>  of the tendency for temperature cycling. It also is their way of
>simplifying
>>  the build to suit different shapes and sizes of lens, although they
>sell
>>  small, medium and large versions. It should avoid problems with badly
>>  attached heat sensors. Presumably the heat sensor is on the collar
>itself or
>>  in the airspace, this would result in a slow, but conservative heating
>>  mechanism.
>>
>>  I myself use heated chambers that enclose the stage and objectives,
>with a
>>  sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.
>>
>>  See link:
>http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
>  > Warmers
>>
>>
>>  Caveats: I haven't used any commercial objective heaters,
>>  No commercial affiliation with any objective heater companies.
>>
>>  --
>>  Stephen H. Cody
>
>Dan Focht
>[hidden email]
>Bioptechs, Inc.
>3560 Beck Rd.
>Butler, PA 16002
>www.bioptechs.com
>Direct 724-282-7145
>Fax [phone]
>Toll Free 877 LIVE-CELL - (548-3235)
>
>________________________________
>
>No virus found in this message.
>Checked by AVG - www.avg.com
>Version: 10.0.1204 / Virus Database: 1498/3534 - Release Date: 03/27/11

--
***************************************************************************
Prof. James B. Pawley,                          Ph.
608-238-3953                        
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver Canada
Info: http://www.3dcourse.ubc.ca/            Applications due by March 15, 2011
               "If it ain't diffraction, it must be statistics." Anon.

[Guy Cox-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I certainly wasn't advocating going to 50C as a routine practice - my
point was that gradients were likely to be more damaging than absolute
temperature.  As to pol lenses - I think it's just selection.  They
simply pick out the ones which don't show any strain.  I know all the
manufacturers read this but I'll bet not one answers!

                                  Guy

Sponsor my next half-marathon on May 15th
There's a special reason - find it out at
http://www.everydayhero.com.au/Guy_Cox_4846
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon)
Australian Centre for Microscopy & Microanalysis,
Madsen Building F09, University of Sydney, NSW 2006

Phone [phone]     Fax [phone]
             Mobile [phone]
______________________________________________
      http://www.guycox.net


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of James Pawley
Sent: Wednesday, 30 March 2011 2:27 PM
To: [hidden email]
Subject: Re: Objective Heaters

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Maybe I should point out to Dan that it was Steve Cody, not Wamer, who
>mentioned their product.  Both Steve and I are interested in the whole
>range of these products simply because we cater for a wide range of
>users, we teach courses for all comers, and (in my case at least) write
>books for the whole gamut of life-science researchers.
>
>
>
>So I would still be interested to get a response from Dan to my query -
>why is it that his controller cannot detect that the heater is detached
>from the lens?  It should be simple.
>
>
>
>As to the temperature a lens can handle, I am sure 50C is not a problem
>but it is vital to heat it slowly - there is a lot of glass there and

it
>is a very poor conductor of heat.  (Brass isn't that good but it's a
lot
>better than glass).  I suspect a body at 50C with optics at 20C would
be
>disastrous.
>
>
>
>
>Guy


Hi Guy and Dan,

I don't have any experience myself but thought that it might be worth
noting that in Chapter 11 (on PSF), Rimas Juskaitis mentions that
when he cycled one lens from RT to 37 deg and back the process
changed the PSF of the lens by a small but detectable amount. Of
course, this wasn't the purpose of the experiment and it is possible
that the lens (or the oil) had not yet regained temperature
equilibrium etc.

However, the change impressed him enough that he mentioned it.

So I am not sure I would want to go to 50 deg. Maybe it might work in
a Pol lens where the lens elements are supposed to be held in such a
way that they are not strained by forces from the mount. I don't know
how they do this but I assume that it means a somewhat more gentle
connection between the brass and glass components. If this is so,
then differences in expansion coefficient between the glass and the
brass may be less likely to distort the shape of the optical surfaces.

Best,

Jim P.

************************************************************************
***
Prof. James B. Pawley,                          Ph.
608-238-3953                        
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver
Canada
Info: http://www.3dcourse.ubc.ca/            Applications due by March
15, 2011
               "If it ain't diffraction, it must be statistics." Anon.

>
>
>Sponsor my next half-marathon on May 15th
>
>There's a special reason - find it out at
>
>http://www.everydayhero.com.au/Guy_Cox_4846
><http://www.everydayhero.com.au/Guy_Cox_4846>
>
>______________________________________________
>
>Associate Professor Guy Cox, MA, DPhil(Oxon)
>
>Australian Centre for Microscopy & Microanalysis,
>
>Madsen Building F09, University of Sydney, NSW 2006
>
>
>
>Phone [phone]     Fax [phone]
>
>              Mobile [phone]
>
>______________________________________________
>
>       http://www.guycox.net <http://www.guycox.net/>
>
>
>
>From: Confocal Microscopy List

[mailto:[hidden email]]

>On Behalf Of Dan Focht
>Sent: Tuesday, 29 March 2011 7:25 AM
>To: [hidden email]
>Subject: Re: Objective Heaters
>
>
>
>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Stephan
>
>
>I agree that boxing the whole microscope or stage and objective area is
>a solution.
>However, for those who don't want to box the scope for a variety of
>reasons. The following applies.
>
>From the Warner web page:
>"Heat generated by the isolated collar is not directly communicated to
>the objective but is instead distributed around the objective via a
>conducting sleeve."
>
>When I read this my first impression is,  "What?, they intentionally
>isolate the heat source from the objective!"
>That means they rely on radiation, which goes in all directions (not
>just toward the objective)  and a little conductivity from air, another
>inefficient heat transfer means.
>Thermal conductivity of air 0.024 W/(m.oC).  Thermal conductivity of
>brass 109 W/(m.oC). In terms of thermal transfer efficiency, there is

no

>comparison, not even in the ball park!
>
>Again from the Warner site:
>"The conducting sleeve warms the surrounding air, which in turn gently
>warms the objective. This approach allows the apparatus to take full
>advantage of the thermal characteristics of the surrounding air. The
>warmer achieves its task without directly contacting or exposing the
>objective to significant stresses associated with temperature
>gradients."
>
>I look at it this way.
>I know the thermal characteristics of air, and it is poor.
>You have an objective screwed into a nosepiece that you want to warm to
>37 degrees C.
>The objective is about 150 to 225 grams of brass, glass and airspace

not

>to mention the mass of the nosepiece.
>I mention the mass of the nosepiece because it acts as a heat sink
>requiring constant compensation thus  more energy to maintain constant
>temperature.
>
>1. Do you think you can accurately transfer enough heat to warm the
>objective with the additional thermal drain of the nosepiece from an
>air-spaced heat source without excessive heat being produced in the
>vicinity of the objective where it radiates outward and upward?
>
>2. Do you think you can maintain a constant accurate temperature when
>you have to wait for the heat to be transferred through air to get to
>the objective without inducing excessive temperature cycling?
>    It is the inefficiency of heat transfer that causes cycling.  We
>thermally profile objectives to be certain that the surface that heat

is

>transferred from or to is as efficient as possible to minimize
>
>3. If your thermal transfer efficiency is as good as it should be, the
>heat source only has to be only a couple of percent higher than the
>temperature of the objective.
>Given the thermal inefficiency of air, I never even entertained using
>air to conduct heat to an objective.
>However, if someone out there has one of these and would lend it to me
>for a couple of days, I would be glad to do a thermal propagation
>time-lapse of it with our military grade quantitative IR camera.
>It would be in movie form and I would make it available to anyone that
>wants it.  This is a costly thing to do but the data would be worth it.
>
>Note, All four major microscope manufacturers have issued a letter to

me

>that the objectives can withstand up to 50 degrees C.  I thought that
>was generous but understandable.
>The temperature of the objective can get a lot higher than 37 degrees
>while it is sitting in the delivery truck waiting to be delivered.
>
>Note, I refrained from naming other companies in my first reply.  Now
>that the door is open, I guess ,SWAG, I can walk in.
>
>
>Dan
>
>
>
>>  From: Stephen Cody <[hidden email]>
>>  Date: March 27, 2011 10:30:22 PM EDT
>>  To: [hidden email]
>>  Subject: Re: Objective Heaters
>>  Reply-To: Confocal Microscopy List

<[hidden email]>

>>
>>  *****
>>  To join, leave or search the confocal microscopy listserv, go to:
>>  http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>  *****
>>
>>  Dear List,
>>
>>  For the sake of completeness I think the Warner objective heater
>should be
>>  mentioned. This differs slightly from those discussed so far, in

that
>the
>>  heating collar is not directly coupled to the lens. There is instead
a
>>  deliberate air space between the heating collar and lens. Presumably
>this
>>  adds a little capacitance to the heat transfer process. It may
reduce
>some
>>  of the tendency for temperature cycling. It also is their way of
>simplifying
>>  the build to suit different shapes and sizes of lens, although they
>sell
>>  small, medium and large versions. It should avoid problems with
badly
>>  attached heat sensors. Presumably the heat sensor is on the collar
>itself or
>>  in the airspace, this would result in a slow, but conservative
heating

>>  mechanism.
>>
>>  I myself use heated chambers that enclose the stage and objectives,
>with a
>>  sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.
>>
>>  See link:
>http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
>  > Warmers
>>
>>
>>  Caveats: I haven't used any commercial objective heaters,
>>  No commercial affiliation with any objective heater companies.
>>
>>  --
>>  Stephen H. Cody
>
>Dan Focht
>[hidden email]
>Bioptechs, Inc.
>3560 Beck Rd.
>Butler, PA 16002
>www.bioptechs.com
>Direct 724-282-7145
>Fax [phone]
>Toll Free 877 LIVE-CELL - (548-3235)
>
>________________________________
>
>No virus found in this message.
>Checked by AVG - www.avg.com
>Version: 10.0.1204 / Virus Database: 1498/3534 - Release Date: 03/27/11

--
************************************************************************
***
Prof. James B. Pawley,                          Ph.
608-238-3953                        
21. N. Prospect Ave. Madison, WI 53726 USA
[hidden email]
3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver
Canada
Info: http://www.3dcourse.ubc.ca/            Applications due by March
15, 2011
               "If it ain't diffraction, it must be statistics." Anon.

[Dan Focht]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Jim

I wonder if the PSF change was influenced more by the change in  
refractive index of the oil than the objective.
It would be interesting to do a study of a non-fluid coupled lens  
undergoing a 15 degree temperature change vs a fluid coupled lens.
Further more, it would be interesting to investigate the effect on  
the PSF of the differences in oil, gly, and water in that all change  
refractive indexes at different rates.

I don't have the equipment to do it but if somebody else does , and  
the time!, it would reveal interesting results.

Dan





On Mar 29, 2011, at 11:26 PM, James Pawley wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Maybe I should point out to Dan that it was Steve Cody, not Wamer,  
>> who
>> mentioned their product.  Both Steve and I are interested in the  
>> whole
>> range of these products simply because we cater for a wide range of
>> users, we teach courses for all comers, and (in my case at least)  
>> write
>> books for the whole gamut of life-science researchers.
>>
>>
>>
>> So I would still be interested to get a response from Dan to my  
>> query -
>> why is it that his controller cannot detect that the heater is  
>> detached
>> from the lens?  It should be simple.
>>
>>
>>
>> As to the temperature a lens can handle, I am sure 50C is not a  
>> problem
>> but it is vital to heat it slowly - there is a lot of glass there  
>> and it
>> is a very poor conductor of heat.  (Brass isn't that good but it's  
>> a lot
>> better than glass).  I suspect a body at 50C with optics at 20C  
>> would be
>> disastrous.
>>
>>
>>
>>
>> Guy
>
>
> Hi Guy and Dan,
>
> I don't have any experience myself but thought that it might be  
> worth noting that in Chapter 11 (on PSF), Rimas Juskaitis mentions  
> that when he cycled one lens from RT to 37 deg and back the process  
> changed the PSF of the lens by a small but detectable amount. Of  
> course, this wasn't the purpose of the experiment and it is  
> possible that the lens (or the oil) had not yet regained  
> temperature equilibrium etc.
>
> However, the change impressed him enough that he mentioned it.
>
> So I am not sure I would want to go to 50 deg. Maybe it might work  
> in a Pol lens where the lens elements are supposed to be held in  
> such a way that they are not strained by forces from the mount. I  
> don't know how they do this but I assume that it means a somewhat  
> more gentle connection between the brass and glass components. If  
> this is so, then differences in expansion coefficient between the  
> glass and the brass may be less likely to distort the shape of the  
> optical surfaces.
>
> Best,
>
> Jim P.
>
> **********************************************************************
> *****
> Prof. James B. Pawley,                          Ph.  
> 608-238-3953                         21. N. Prospect Ave. Madison,  
> WI 53726 USA [hidden email]
> 3D Microscopy of Living Cells Course, June 11-23, 2011, UBC,  
> Vancouver Canada
> Info: http://www.3dcourse.ubc.ca/            Applications due by March 15,  
> 2011
>       "If it ain't diffraction, it must be statistics." Anon.
>>
>>
>> Sponsor my next half-marathon on May 15th
>>
>> There's a special reason - find it out at
>>
>> http://www.everydayhero.com.au/Guy_Cox_4846
>> <http://www.everydayhero.com.au/Guy_Cox_4846>
>>
>> ______________________________________________
>>
>> Associate Professor Guy Cox, MA, DPhil(Oxon)
>>
>> Australian Centre for Microscopy & Microanalysis,
>>
>> Madsen Building F09, University of Sydney, NSW 2006
>>
>>
>>
>> Phone [phone]     Fax [phone]
>>
>>              Mobile [phone]
>>
>> ______________________________________________
>>
>>       http://www.guycox.net <http://www.guycox.net/>
>>
>>
>>
>> From: Confocal Microscopy List  
>> [mailto:[hidden email]]
>> On Behalf Of Dan Focht
>> Sent: Tuesday, 29 March 2011 7:25 AM
>> To: [hidden email]
>> Subject: Re: Objective Heaters
>>
>>
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Stephan
>>
>>
>> I agree that boxing the whole microscope or stage and objective  
>> area is
>> a solution.
>> However, for those who don't want to box the scope for a variety of
>> reasons. The following applies.
>>
>> From the Warner web page:
>> "Heat generated by the isolated collar is not directly  
>> communicated to
>> the objective but is instead distributed around the objective via a
>> conducting sleeve."
>>
>> When I read this my first impression is,  "What?, they intentionally
>> isolate the heat source from the objective!"
>> That means they rely on radiation, which goes in all directions (not
>> just toward the objective)  and a little conductivity from air,  
>> another
>> inefficient heat transfer means.
>> Thermal conductivity of air 0.024 W/(m.oC).  Thermal conductivity of
>> brass 109 W/(m.oC). In terms of thermal transfer efficiency, there  
>> is no
>> comparison, not even in the ball park!
>>
>> Again from the Warner site:
>> "The conducting sleeve warms the surrounding air, which in turn  
>> gently
>> warms the objective. This approach allows the apparatus to take full
>> advantage of the thermal characteristics of the surrounding air. The
>> warmer achieves its task without directly contacting or exposing the
>> objective to significant stresses associated with temperature
>> gradients."
>>
>> I look at it this way.
>> I know the thermal characteristics of air, and it is poor.
>> You have an objective screwed into a nosepiece that you want to  
>> warm to
>> 37 degrees C.
>> The objective is about 150 to 225 grams of brass, glass and  
>> airspace not
>> to mention the mass of the nosepiece.
>> I mention the mass of the nosepiece because it acts as a heat sink
>> requiring constant compensation thus  more energy to maintain  
>> constant
>> temperature.
>>
>> 1. Do you think you can accurately transfer enough heat to warm the
>> objective with the additional thermal drain of the nosepiece from an
>> air-spaced heat source without excessive heat being produced in the
>> vicinity of the objective where it radiates outward and upward?
>>
>> 2. Do you think you can maintain a constant accurate temperature when
>> you have to wait for the heat to be transferred through air to get to
>> the objective without inducing excessive temperature cycling?    
>> It is the inefficiency of heat transfer that causes cycling.  We
>> thermally profile objectives to be certain that the surface that  
>> heat is
>> transferred from or to is as efficient as possible to minimize
>>
>> 3. If your thermal transfer efficiency is as good as it should be,  
>> the
>> heat source only has to be only a couple of percent higher than the
>> temperature of the objective.
>> Given the thermal inefficiency of air, I never even entertained using
>> air to conduct heat to an objective.
>> However, if someone out there has one of these and would lend it  
>> to me
>> for a couple of days, I would be glad to do a thermal propagation
>> time-lapse of it with our military grade quantitative IR camera.
>> It would be in movie form and I would make it available to anyone  
>> that
>> wants it.  This is a costly thing to do but the data would be  
>> worth it.
>>
>> Note, All four major microscope manufacturers have issued a letter  
>> to me
>> that the objectives can withstand up to 50 degrees C.  I thought that
>> was generous but understandable.
>> The temperature of the objective can get a lot higher than 37 degrees
>> while it is sitting in the delivery truck waiting to be delivered.
>>
>> Note, I refrained from naming other companies in my first reply.  Now
>> that the door is open, I guess ,SWAG, I can walk in.
>>
>>
>> Dan
>>
>>
>>
>>>  From: Stephen Cody <[hidden email]>
>>>  Date: March 27, 2011 10:30:22 PM EDT
>>>  To: [hidden email]
>>>  Subject: Re: Objective Heaters
>>>  Reply-To: Confocal Microscopy List  
>>> <[hidden email]>
>>>
>>>  *****
>>>  To join, leave or search the confocal microscopy listserv, go to:
>>>  http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>  *****
>>>
>>>  Dear List,
>>>
>>>  For the sake of completeness I think the Warner objective heater
>> should be
>>>  mentioned. This differs slightly from those discussed so far, in  
>>> that
>> the
>>>  heating collar is not directly coupled to the lens. There is  
>>> instead a
>>>  deliberate air space between the heating collar and lens.  
>>> Presumably
>> this
>>>  adds a little capacitance to the heat transfer process. It may  
>>> reduce
>> some
>>>  of the tendency for temperature cycling. It also is their way of
>> simplifying
>>>  the build to suit different shapes and sizes of lens, although they
>> sell
>>>  small, medium and large versions. It should avoid problems with  
>>> badly
>>>  attached heat sensors. Presumably the heat sensor is on the collar
>> itself or
>>>  in the airspace, this would result in a slow, but conservative  
>>> heating
>>>  mechanism.
>>>
>>>  I myself use heated chambers that enclose the stage and objectives,
>> with a
>>>  sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.
>>>
>>>  See link:
>> http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
>>  > Warmers
>>>
>>>
>>>  Caveats: I haven't used any commercial objective heaters,
>>>  No commercial affiliation with any objective heater companies.
>>>
>>>  --
>>>  Stephen H. Cody
>>
>> Dan Focht
>> [hidden email]
>> Bioptechs, Inc.
>> 3560 Beck Rd.
>> Butler, PA 16002
>> www.bioptechs.com
>> Direct 724-282-7145
>> Fax [phone]
>> Toll Free 877 LIVE-CELL - (548-3235)
>>
>> ________________________________
>>
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1204 / Virus Database: 1498/3534 - Release Date:  
>> 03/27/11
>
>
> --
> **********************************************************************
> *****
> Prof. James B. Pawley,                          Ph.  
> 608-238-3953                         21. N. Prospect Ave. Madison,  
> WI 53726 USA [hidden email]
> 3D Microscopy of Living Cells Course, June 11-23, 2011, UBC,  
> Vancouver Canada
> Info: http://www.3dcourse.ubc.ca/            Applications due by March 15,  
> 2011
>       "If it ain't diffraction, it must be statistics." Anon.

Dan Focht
[hidden email]
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
Direct 724-282-7145
Fax [phone]
Toll Free 877 LIVE-CELL - (548-3235)

[Dan Focht]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Guy

The Bioptechs series 5 Objective Heater System was not designed to detect the presence of an objective because we did not think anybody would run it without being attached to an objective.
However, it has happened although not often.  In our next series of Bioptechs Objective heaters we will include that feature.  
We are always responsible to our customers request and that is a good one.
When I get back from AACR I will begin implementing this feature.

Note, that the instructions indicate that the operator should never run the objective heater without a load and should observe the digital display to confirm proper expected operation.

One reason the controller does not detect the presence of an objective is that the temperature sensor is always at rom temp at the beginning of the heating process.
Therefore, room temp is expected and not out of the ordinary.  Also given the differences to thermal profiles of different objectives and different potential sources of heat that could influence the sensor we cant always look for a heat rise to occur.  What I will do is to place a pressure sensor on the heater "cube", BTW the machinist already thinks it is Swiss Cheese given all the holes in it, to not allow the activation of the heating circuit until the heater cube is secured firmly against the objective.  That should do it!

I have never suggested or advised that an objective should be heated as high as 50 degree C. I was just illustrating the acceptable range as allowed by manufacturers.
I know it was Stephen Cody that mentioned Warner, Thank you Stephen!


Dan

> Maybe I should point out to Dan that it was Steve Cody, not Wamer, who
> mentioned their product.  Both Steve and I are interested in the whole
> range of these products simply because we cater for a wide range of
> users, we teach courses for all comers, and (in my case at least) write
> books for the whole gamut of life-science researchers.
>
>
>
> So I would still be interested to get a response from Dan to my query -
> why is it that his controller cannot detect that the heater is detached
> from the lens?  It should be simple.
>
>
>
> As to the temperature a lens can handle, I am sure 50C is not a problem
> but it is vital to heat it slowly - there is a lot of glass there and it
> is a very poor conductor of heat.  (Brass isn't that good but it's a lot
> better than glass).  I suspect a body at 50C with optics at 20C would be
> disastrous.

On Mar 28, 2011, at 4:24 PM, Dan Focht wrote:

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Stephan


I agree that boxing the whole microscope or stage and objective area is a solution.  
However, for those who don't want to box the scope for a variety of reasons. The following applies.

From the Warner web page:
"Heat generated by the isolated collar is not directly communicated to the objective but is instead distributed around the objective via a conducting sleeve."

When I read this my first impression is,  "What?, they intentionally isolate the heat source from the objective!"
That means they rely on radiation, which goes in all directions (not just toward the objective)  and a little conductivity from air, another inefficient heat transfer means.  
Thermal conductivity of air 0.024 W/(m.oC).  Thermal conductivity of brass 109 W/(m.oC). In terms of thermal transfer efficiency, there is no comparison, not even in the ball park!

Again from the Warner site:
"The conducting sleeve warms the surrounding air, which in turn gently warms the objective. This approach allows the apparatus to take full advantage of the thermal characteristics of the surrounding air. The warmer achieves its task without directly contacting or exposing the objective to significant stresses associated with temperature gradients."

I look at it this way.  
I know the thermal characteristics of air, and it is poor.  
You have an objective screwed into a nosepiece that you want to warm to 37 degrees C.  
The objective is about 150 to 225 grams of brass, glass and airspace not to mention the mass of the nosepiece.
I mention the mass of the nosepiece because it acts as a heat sink requiring constant compensation thus  more energy to maintain constant temperature.

1. Do you think you can accurately transfer enough heat to warm the objective with the additional thermal drain of the nosepiece from an air-spaced heat source without excessive heat being produced in the vicinity of the objective where it radiates outward and upward?  

2. Do you think you can maintain a constant accurate temperature when you have to wait for the heat to be transferred through air to get to the objective without inducing excessive temperature cycling?  
  It is the inefficiency of heat transfer that causes cycling.  We thermally profile objectives to be certain that the surface that heat is transferred from or to is as efficient as possible to minimize

3. If your thermal transfer efficiency is as good as it should be, the heat source only has to be only a couple of percent higher than the temperature of the objective.
Given the thermal inefficiency of air, I never even entertained using air to conduct heat to an objective.  
However, if someone out there has one of these and would lend it to me for a couple of days, I would be glad to do a thermal propagation time-lapse of it with our military grade quantitative IR camera.
It would be in movie form and I would make it available to anyone that wants it.  This is a costly thing to do but the data would be worth it.  

Note, All four major microscope manufacturers have issued a letter to me that the objectives can withstand up to 50 degrees C.  I thought that was generous but understandable.  
The temperature of the objective can get a lot higher than 37 degrees while it is sitting in the delivery truck waiting to be delivered.

Note, I refrained from naming other companies in my first reply.  Now that the door is open, I guess ,SWAG, I can walk in.


Dan

> From: Stephen Cody <[hidden email]>
> Date: March 27, 2011 10:30:22 PM EDT
> To: [hidden email]
> Subject: Re: Objective Heaters
> Reply-To: Confocal Microscopy List <[hidden email]>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear List,
>
> For the sake of completeness I think the Warner objective heater should be
> mentioned. This differs slightly from those discussed so far, in that the
> heating collar is not directly coupled to the lens. There is instead a
> deliberate air space between the heating collar and lens. Presumably this
> adds a little capacitance to the heat transfer process. It may reduce some
> of the tendency for temperature cycling. It also is their way of simplifying
> the build to suit different shapes and sizes of lens, although they sell
> small, medium and large versions. It should avoid problems with badly
> attached heat sensors. Presumably the heat sensor is on the collar itself or
> in the airspace, this would result in a slow, but conservative heating
> mechanism.
>
> I myself use heated chambers that enclose the stage and objectives, with a
> sub-incubator to control CO2 / Oxygen / Nitrogen and humidity.
>
> See link: http://www.warneronline.com/product_info.cfm?id=1365&name=Objective
> Warmers
>
>
> Caveats: I haven't used any commercial objective heaters,
> No commercial affiliation with any objective heater companies.
>
> --
> Stephen H. Cody

Dan Focht
[hidden email]
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
Direct 724-282-7145
Fax [phone]
Toll Free 877 LIVE-CELL - (548-3235)

Dan Focht
Bioptechs, Inc.
3560 Beck Rd.
Butler, PA 16002
www.bioptechs.com
P: [phone]
F: [phone]
[hidden email]