PMT module and electronic interferences

[Ben Melchior]

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

Hi Listers,

I have a technical question regarding the tuning of PMT modules on a confocal
system.

We have recently replaced a PMT module on our LSM5 system.  Although we
now can get a signal and observe our cells we still having what looks like
electrical interferences (horizontal stripes) that impact the quality of our
images when scanning.
The image acquisition now requires a much lower laser power (633nm line)
than previous, but inversely, an extreme detector gain was needed (over
1100!). If I try to increase the laser power and decrease the PMT voltage it
looks like the PMT saturates or there is no more signal.
Other channels/lines have clean signal. Nothing wrong with the optics.

Is there any electronic engineer or specialist with any thoughts regarding
adjustments, tweaking, or calibration of the PMT module? Or any pin on the
board that I should check to see if the control voltage to the PMT is right?

Thank you,

Ben

[Rosemary.White]

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

Hi Ben,

Not sure if this will be your problem, but our new SP8 is sensitive to
electronic interference - no wifi or mobile phone use in the SP8 room or
you get horizontal interference similar to what you describe.

cheers,
Rosemary

Dr Rosemary White
CSIRO Plant Industry
GPO Box 1600
Canberra, ACT 2601
Australia

T 61 2 6246 5475
F 61 2 6246 5334
E [hidden email]

On 14/12/12 10:07 AM, "Ben Melchior" <[hidden email]> wrote:

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Hi Listers,
>
>I have a technical question regarding the tuning of PMT modules on a
>confocal
>system.
>
>We have recently replaced a PMT module on our LSM5 system.  Although we
>now can get a signal and observe our cells we still having what looks
>like
>electrical interferences (horizontal stripes) that impact the quality of
>our
>images when scanning.
>The image acquisition now requires a much lower laser power (633nm line)
>than previous, but inversely, an extreme detector gain was needed (over
>1100!). If I try to increase the laser power and decrease the PMT voltage
>it
>looks like the PMT saturates or there is no more signal.
>Other channels/lines have clean signal. Nothing wrong with the optics.
>
>Is there any electronic engineer or specialist with any thoughts
>regarding
>adjustments, tweaking, or calibration of the PMT module? Or any pin on
>the
>board that I should check to see if the control voltage to the PMT is
>right?
>
>Thank you,
>
>Ben

[George McNamara]

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

Have Zeiss replace the replacement with a new unit (both PMT and HV
board) that works correctly.

On 12/13/2012 6:07 PM, Ben Melchior wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi Listers,
>
> I have a technical question regarding the tuning of PMT modules on a confocal
> system.
>
> We have recently replaced a PMT module on our LSM5 system.  Although we
> now can get a signal and observe our cells we still having what looks like
> electrical interferences (horizontal stripes) that impact the quality of our
> images when scanning.
> The image acquisition now requires a much lower laser power (633nm line)
> than previous, but inversely, an extreme detector gain was needed (over
> 1100!). If I try to increase the laser power and decrease the PMT voltage it
> looks like the PMT saturates or there is no more signal.
> Other channels/lines have clean signal. Nothing wrong with the optics.
>
> Is there any electronic engineer or specialist with any thoughts regarding
> adjustments, tweaking, or calibration of the PMT module? Or any pin on the
> board that I should check to see if the control voltage to the PMT is right?
>
> Thank you,
>
> Ben
>
>    

[Pascal Weber]

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

Hi everebody,

I had heard about the problem of sensitivity of PMT has been set by a technician
linearization sensitivity. (Procedure to apply)
For sensitivity to mobile I am very surprised and I do the same test!

[Craig Brideau]

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

It is also possible that the electronics are not grounded properly.  You
can get electronic noise from an improper ground loop.  It's also possible
you have light leaking in from somewhere; I've gotten stripes in images
from flashing LEDs on equipment near the microscope.  A quick piece of
black tape over the offending LED and no more noise!

Craig


On Thu, Dec 13, 2012 at 11:46 PM, Pascal Weber <[hidden email]>wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi everebody,
>
> I had heard about the problem of sensitivity of PMT has been set by a
> technician
> linearization sensitivity. (Procedure to apply)
> For sensitivity to mobile I am very surprised and I do the same test!
>

[Aleem]

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

Increase your exposure time per pixel. It may help, did help in my case.

Good luck.

~Aleem

On Fri, Dec 14, 2012 at 11:59 AM, Craig Brideau <[hidden email]>wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> It is also possible that the electronics are not grounded properly.  You
> can get electronic noise from an improper ground loop.  It's also possible
> you have light leaking in from somewhere; I've gotten stripes in images
> from flashing LEDs on equipment near the microscope.  A quick piece of
> black tape over the offending LED and no more noise!
>
> Craig
>
>
> On Thu, Dec 13, 2012 at 11:46 PM, Pascal Weber <[hidden email]
> >wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Hi everebody,
> >
> > I had heard about the problem of sensitivity of PMT has been set by a
> > technician
> > linearization sensitivity. (Procedure to apply)
> > For sensitivity to mobile I am very surprised and I do the same test!
> >
>

--

[Aleem]

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

And also do not use the computer for anything during scanning. It can give
you artifacts in the final image.

~aleem

On Fri, Dec 14, 2012 at 12:03 PM, Aleem Syed <[hidden email]> wrote:

> Increase your exposure time per pixel. It may help, did help in my case.
>
> Good luck.
>
> ~Aleem
>
>
> On Fri, Dec 14, 2012 at 11:59 AM, Craig Brideau <[hidden email]>wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> It is also possible that the electronics are not grounded properly.  You
>> can get electronic noise from an improper ground loop.  It's also possible
>> you have light leaking in from somewhere; I've gotten stripes in images
>> from flashing LEDs on equipment near the microscope.  A quick piece of
>> black tape over the offending LED and no more noise!
>>
>> Craig
>>
>>
>> On Thu, Dec 13, 2012 at 11:46 PM, Pascal Weber <[hidden email]
>> >wrote:
>>
>> > *****
>> > To join, leave or search the confocal microscopy listserv, go to:
>> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> > *****
>> >
>> > Hi everebody,
>> >
>> > I had heard about the problem of sensitivity of PMT has been set by a
>> > technician
>> > linearization sensitivity. (Procedure to apply)
>> > For sensitivity to mobile I am very surprised and I do the same test!
>> >
>>
>
>
>
> --
>
>

--
Aleem Syed
Graduate Student,
Dr. Smith Group,
0712 Gilman Hall,
Iowa State University
Ames 50011
USA

*Success and Failure are part of life, truth is none of 'em  is permanent,
including Life....*

[Zdenek Svindrych]

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

Hi Ben,

I do not know your system, but in general, you ALWAYS can decrease the PMT
gain if you simultaneously increase the laser power. If this does not work,
there are several points to check:
1) the laser - when you increase the power you should see more light at the
sample (which is obvious)
2) wrong offset setting - a value of zero is usually a good starting point
(at least on Leica's)
3) replace the replacement (as suggested by other members of the list).
4) a VERY peculiar sample, worth a paper in Nature and a milestone in
superresolution imaging (based on nonlinear effect).

You say that with other lasers it works fine. Do you mean the same PMT?
There's no reason why a PMT should work with one color and not the others...

And regarding the stripes, if the pinhole is set properly, ambient light
should not affect the result. The cause may be an unstable laser or
defective detector (or its supply).

Regards,

deden


On Thu, 13 Dec 2012 17:07:52 -0600, Ben Melchior <[hidden email]> wrote:

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Hi Listers,
>
>I have a technical question regarding the tuning of PMT modules on a confocal
>system.
>
>We have recently replaced a PMT module on our LSM5 system.  Although we
>now can get a signal and observe our cells we still having what looks like
>electrical interferences (horizontal stripes) that impact the quality of our
>images when scanning.
>The image acquisition now requires a much lower laser power (633nm line)
>than previous, but inversely, an extreme detector gain was needed (over
>1100!). If I try to increase the laser power and decrease the PMT voltage it
>looks like the PMT saturates or there is no more signal.
>Other channels/lines have clean signal. Nothing wrong with the optics.
>
>Is there any electronic engineer or specialist with any thoughts regarding
>adjustments, tweaking, or calibration of the PMT module? Or any pin on the
>board that I should check to see if the control voltage to the PMT is right?
>
>Thank you,
>
>Ben