Scanner and vibrations

[Vladimir Ghukasyan]

Dear Listers,

I'm doing a set of experiments which requires high magnification (60x
objective + x36 pan zoom) on our confocal Olympus FV1000. the
microscope is placed on the air table, which do not touch any wall or
tables around.
Imaging was going well, but at some point I started to see a zigzag
pattern in the scanning, similar to that one gets when the air table
is lucking nitrogen. This seems not to be a problem of the scanner
itself, using a separate scanning unit delivers the same zigzag.

The lab is on the 7th floor, but this shouldn't be the case as for
about a month the imaging was going well.

I'm wondering what could be a source of this problem in a typical lab,
and what could be done to overcome it.

Thank you in advance,
Vladimir Ghukasyan

[Periasamy, Ammasi (ap3t)]

Vladimir
Seventh floor is not a good place for a microscopy system. If someone somewhere banging the wall or drilling in the building, the unit may pick up the vibration. Or make sure there is no autoclave or any high voltage unit is operating in the same electrical line coming to your microscopy room. Do you have the UPS for the confocal unit?
The suggestion is get down to the basement or first floor!!

Prof. Ammasi Periasamy
Director, Keck Center for Cellular Imaging (KCCI)
Professor of Biology and Biomedical Engineering
Biology, Gilmer Hall (064), 485 McCormick Rd
University of Virginia
Charlottesville, VA 22904
Voice: 434-243-7602 (Office); 982-4869 (lab)
Fax:[phone]; Email:[hidden email]
http://www.kcci.virginia.edu/Contact/peri.php
************************
10th Annual Workshop on FRET Microscopy, March 8-13, 2011
http://www.kcci.virginia.edu/workshop/workshop2011/index.php
*************************


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Vladimir Ghukasyan
Sent: Tuesday, August 10, 2010 3:59 PM
To: [hidden email]
Subject: Scanner and vibrations

Dear Listers,

I'm doing a set of experiments which requires high magnification (60x
objective + x36 pan zoom) on our confocal Olympus FV1000. the
microscope is placed on the air table, which do not touch any wall or
tables around.
Imaging was going well, but at some point I started to see a zigzag
pattern in the scanning, similar to that one gets when the air table
is lucking nitrogen. This seems not to be a problem of the scanner
itself, using a separate scanning unit delivers the same zigzag.

The lab is on the 7th floor, but this shouldn't be the case as for
about a month the imaging was going well.

I'm wondering what could be a source of this problem in a typical lab,
and what could be done to overcome it.

Thank you in advance,
Vladimir Ghukasyan

[John Oreopoulos]

Could that be due to placement of the scope near power lines (or some other large pice of electrical equipment) with a strong EMF that mess up the scanner galvos? Was there any recent electrical work done near the lab in the last month? Maybe the problem has always been there but you didn't notice it until you started using such high magnification?

John Oreopoulos


On 2010-08-10, at 3:58 PM, Vladimir Ghukasyan wrote:

> Dear Listers,
>
> I'm doing a set of experiments which requires high magnification (60x
> objective + x36 pan zoom) on our confocal Olympus FV1000. the
> microscope is placed on the air table, which do not touch any wall or
> tables around.
> Imaging was going well, but at some point I started to see a zigzag
> pattern in the scanning, similar to that one gets when the air table
> is lucking nitrogen. This seems not to be a problem of the scanner
> itself, using a separate scanning unit delivers the same zigzag.
>
> The lab is on the 7th floor, but this shouldn't be the case as for
> about a month the imaging was going well.
>
> I'm wondering what could be a source of this problem in a typical lab,
> and what could be done to overcome it.
>
> Thank you in advance,
> Vladimir Ghukasyan

[mmodel]

Some time ago I asked a similar question for Olympus 500. Our zigzagging was definitely not due to vibrations. We never figured out what it was, at some point (after Olympus for the fifth time took everything apart and put back together) it stopped. Good luck!

Mike

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Vladimir Ghukasyan
Sent: Tuesday, August 10, 2010 3:59 PM
To: [hidden email]
Subject: Scanner and vibrations

Dear Listers,

I'm doing a set of experiments which requires high magnification (60x
objective + x36 pan zoom) on our confocal Olympus FV1000. the
microscope is placed on the air table, which do not touch any wall or
tables around.
Imaging was going well, but at some point I started to see a zigzag
pattern in the scanning, similar to that one gets when the air table
is lucking nitrogen. This seems not to be a problem of the scanner
itself, using a separate scanning unit delivers the same zigzag.

The lab is on the 7th floor, but this shouldn't be the case as for
about a month the imaging was going well.

I'm wondering what could be a source of this problem in a typical lab,
and what could be done to overcome it.

Thank you in advance,
Vladimir Ghukasyan

[Johannes Helm]

Good evening,

unfortunately, not an unknown problem to us as to many others.
In two cases - an old style "TCS-SP" by Leica and an "FV300" by Olympus -,
the pattern was the consequence of vibrations being transferred from parts
of the systems including fans to the optical tabletop by way of stiff
cables connecting the namely parts of the system to the actual scanner
head.
In both cases, we got rid of it by making sure that the cables were
channeled through some holders including the kind of "air pads", which one
uses to protect sensitive products in transportation boxes. I beg your
pardon for my ignorance in English, I do not know the proper expression
for these pads.

Another case was with an old Sarastro p4d. There, the main fan providing
the air for the forced ventilation of the laser managed to establish a
standing acoustical wave in the lab. Since the air was pressed through a
long, soft and flexible tube, it was possible to place the fan outside the
lab and the problem vanished.

Best wishes,

Johannes


--
P. Johannes Helm, M.Sc. PhD
Seniorengineer
CMBN
University of Oslo
Institute of Basic Medical Science
Department of Anatomy
Postboks 1105 - Blindern
NO-0317 Oslo

Voice: [phone]
Fax: [phone]

WWW: folk.uio.no/jhelm

> Dear Listers,
>
> I'm doing a set of experiments which requires high magnification (60x
> objective + x36 pan zoom) on our confocal Olympus FV1000. the
> microscope is placed on the air table, which do not touch any wall or
> tables around.
> Imaging was going well, but at some point I started to see a zigzag
> pattern in the scanning, similar to that one gets when the air table
> is lucking nitrogen. This seems not to be a problem of the scanner
> itself, using a separate scanning unit delivers the same zigzag.
>
> The lab is on the 7th floor, but this shouldn't be the case as for
> about a month the imaging was going well.
>
> I'm wondering what could be a source of this problem in a typical lab,
> and what could be done to overcome it.
>
> Thank you in advance,
> Vladimir Ghukasyan
>

[Urs Utzinger]

Vladimir, I am trying to solve a similar problem.

Largest improvement so far was the replacement of the fans that were cooling
the electronics in the confocal  scan unit. Often it is possible to halt the
fans while continuing with the imaging to test which one is causing most of
the vibrations. One can lower the speed of DC-fans by placing a resistor in
series with the motor. If there are no fans in equipment that is
mechanically connected to your microscope then this should cause your
problem.

You should remove any equipment that has fans or vibrating parts from the
optics table and place it underneath or on racks above the table (racks
should not be mounted to the table). For example it is not a good idea to
add a computer that controls other components of your setup and place it
onto the table. That would defeat the purpose of the floating table.

The scanner's control electronics can also oscillate and it is not trivial
to adjust its control loop to reduce the vibrations. It should not be
necessary to do that as you system was optimized at the factory. However if
for example the heater for the position sensor in your scanner feedback loop
fails, it might start to oscillate.

I heard that the vibrations might also vary with the pressure and extensions
of the air cylinders in the legs in your table. It might be worth checking
if the pressure gages match the recommended settings.

I am less convinced that magnetic field pickup is an issue. Also if you have
a good air table it should isolate vibrations from other activities in the
building. You could check for this by measuring at 2 am when traffic in and
outside the building is low and most equipment is off. If the vibrations are
gone you might need to add additional dampers below the legs of your table.
The legs of your table are a low pass filter. If you put two filters in
series, suppression should add. I believe there are floor elements one can
install in addition to an air-table. That could be cheaper than relocating
your equipment. If one leg is not floating, the other three can not
compensate for it. Your table manual would state how to correct for this.

Urs Utzinger
University of Arizona

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On
Behalf Of Vladimir Ghukasyan
Sent: Tuesday, August 10, 2010 12:59 PM
To: [hidden email]
Subject: Scanner and vibrations

Dear Listers,

I'm doing a set of experiments which requires high magnification (60x
objective + x36 pan zoom) on our confocal Olympus FV1000. the microscope is
placed on the air table, which do not touch any wall or tables around.
Imaging was going well, but at some point I started to see a zigzag pattern
in the scanning, similar to that one gets when the air table is lucking
nitrogen. This seems not to be a problem of the scanner itself, using a
separate scanning unit delivers the same zigzag.

The lab is on the 7th floor, but this shouldn't be the case as for about a
month the imaging was going well.

I'm wondering what could be a source of this problem in a typical lab, and
what could be done to overcome it.

Thank you in advance,
Vladimir Ghukasyan


DISCLAIMER: This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.

[Tim Feinstein-2]

We have had a similar result with an older UltraView spinning disc system.  After we removed everything possible from the light table and stood everything else on small squares of vibration-isolating carpet pad our vibration issues went down dramatically.  Our room was underground and isolated from power lines and other common EM interference, so your mileage may vary.  

All the best,


Tim Feinstein
University of Pittsburgh


On Aug 10, 2010, at 9:57 PM, Urs Utzinger wrote:

> Vladimir, I am trying to solve a similar problem.
>
> Largest improvement so far was the replacement of the fans that were cooling
> the electronics in the confocal  scan unit. Often it is possible to halt the
> fans while continuing with the imaging to test which one is causing most of
> the vibrations. One can lower the speed of DC-fans by placing a resistor in
> series with the motor. If there are no fans in equipment that is
> mechanically connected to your microscope then this should cause your
> problem.
>
> You should remove any equipment that has fans or vibrating parts from the
> optics table and place it underneath or on racks above the table (racks
> should not be mounted to the table). For example it is not a good idea to
> add a computer that controls other components of your setup and place it
> onto the table. That would defeat the purpose of the floating table.
>
> The scanner's control electronics can also oscillate and it is not trivial
> to adjust its control loop to reduce the vibrations. It should not be
> necessary to do that as you system was optimized at the factory. However if
> for example the heater for the position sensor in your scanner feedback loop
> fails, it might start to oscillate.
>
> I heard that the vibrations might also vary with the pressure and extensions
> of the air cylinders in the legs in your table. It might be worth checking
> if the pressure gages match the recommended settings.
>
> I am less convinced that magnetic field pickup is an issue. Also if you have
> a good air table it should isolate vibrations from other activities in the
> building. You could check for this by measuring at 2 am when traffic in and
> outside the building is low and most equipment is off. If the vibrations are
> gone you might need to add additional dampers below the legs of your table.
> The legs of your table are a low pass filter. If you put two filters in
> series, suppression should add. I believe there are floor elements one can
> install in addition to an air-table. That could be cheaper than relocating
> your equipment. If one leg is not floating, the other three can not
> compensate for it. Your table manual would state how to correct for this.
>
> Urs Utzinger
> University of Arizona
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On
> Behalf Of Vladimir Ghukasyan
> Sent: Tuesday, August 10, 2010 12:59 PM
> To: [hidden email]
> Subject: Scanner and vibrations
>
> Dear Listers,
>
> I'm doing a set of experiments which requires high magnification (60x
> objective + x36 pan zoom) on our confocal Olympus FV1000. the microscope is
> placed on the air table, which do not touch any wall or tables around.
> Imaging was going well, but at some point I started to see a zigzag pattern
> in the scanning, similar to that one gets when the air table is lucking
> nitrogen. This seems not to be a problem of the scanner itself, using a
> separate scanning unit delivers the same zigzag.
>
> The lab is on the 7th floor, but this shouldn't be the case as for about a
> month the imaging was going well.
>
> I'm wondering what could be a source of this problem in a typical lab, and
> what could be done to overcome it.
>
> Thank you in advance,
> Vladimir Ghukasyan
>
>
> DISCLAIMER: This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.