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Posted: 4/12/2006 4:32:18 PM EDT
[Last Edit: 4/12/2006 4:41:37 PM EDT by ffsparky26]
Hello all

Does anyone on the board have and experience with the Keithley 6517A Electrometer? Specifically with the relative measurement function and setting it via GPIB.

I can not for the life of me get this damn thing to accquire the current for the relative measurement and then subtract it from the other readings.

I know this is specialized equipment but maybe someone has some experience.

I called Keithley Tech Support and they put an engineer on it. It seems he can't figure it out either. Pretty damn sad, but I need to have this working by this Friday.

I can do measurements without the realative measurement, but only to 2.5 picoamps. That seems to be the noise floor.

I thought I had it working, but then I made some measurements and it didn't look like it was subtracting any value from the measurements. Then I sent the commadn via GPIB to read the realative value it read back zero.

Link Posted: 4/12/2006 4:37:21 PM EDT
Say what????


Bump

Had to do something, my name is Keith
Link Posted: 4/12/2006 5:25:45 PM EDT
A bump cus I need some input for KSPhysicist or some of the others who have experience with this.
Link Posted: 4/12/2006 5:35:07 PM EDT

Just curious . Why would you need to measure current that low ? Gas Chromotography ?
Link Posted: 4/12/2006 5:44:40 PM EDT

Originally Posted By djohns6:
Just curious . Why would you need to measure current that low ? Gas Chromotography ?



Well there are a lot of reasons to measure currents that small from charcterizing semiconductors and superconductors to neurophysiology where you are measuring the current when a neruon fires.

My application is for a radiation detection scheme where I have 10 Argonne filled Ionization Chamber. It is basically a tube with a wire run through it. The tube is filled with argonne and there is a voltage bias applied across the tube. As the gamma ray interact with the gas the free electrons gater on the wire. You measure the current coming from the wire and the current is proportional to the radiation exposure on the tube.

This current is in the sub pico amp range for dose rates of less than 1 Rad/hr in my ion chambers.
Link Posted: 4/12/2006 5:47:15 PM EDT

Originally Posted By ffsparky26:
A bump cus I need some input for KSPhysicist or some of the others who have experience with this.



IM him yet?
Link Posted: 4/12/2006 5:50:42 PM EDT
What part of Tennessee are you in? What time this Friday are you needing this working? I am going to be swinging through Tennessee from Virginia this Friday and depending on location and time needed could probably help you out. Even though I am not familiar with that particular piece of test equipment I am intimately familiar with numerous others performing similar measurements.
Link Posted: 4/12/2006 5:53:46 PM EDT

Originally Posted By Wingnut116ACW:
What part of Tennessee are you in? What time this Friday are you needing this working? I am going to be swinging through Tennessee from Virginia this Friday and depending on location and time needed could probably help you out. Even though I am not familiar with that particular piece of test equipment I am intimately familiar with numerous others performing similar measurements.



Well I cant get you in to where the equipment is, I am at Oak Ridge, TN.

It would take several weeks to get you through security.

Do you have experience programming Keithley Insturments via GPIB?

Link Posted: 4/12/2006 6:06:07 PM EDT
[Last Edit: 4/12/2006 6:06:40 PM EDT by wildearp]
I used to work on these:

http://www.esi.com/esi/products/ecs/test/



You may be able to do some tire kicking and talk to a programmer, if they haven't layed them all off, yet. As you can see, there are several of the systems that use the various Keithley meters.

Link Posted: 4/12/2006 6:10:16 PM EDT
[Last Edit: 4/12/2006 6:11:15 PM EDT by Wingnut116ACW]

Originally Posted By ffsparky26:

Originally Posted By Wingnut116ACW:
What part of Tennessee are you in? What time this Friday are you needing this working? I am going to be swinging through Tennessee from Virginia this Friday and depending on location and time needed could probably help you out. Even though I am not familiar with that particular piece of test equipment I am intimately familiar with numerous others performing similar measurements.



Well I cant get you in to where the equipment is, I am at Oak Ridge, TN.

It would take several weeks to get you through security.

Do you have experience programming Keithley Insturments via GPIB?




Fair enough, I work in similar facilities on a regular basis. I have been working, until quite recently, in a satcom test lab working on automating test procedues via GPIB. Any openings there? Always looking for new and exciting places to work.
Link Posted: 4/12/2006 6:55:50 PM EDT
[Last Edit: 4/12/2006 6:57:08 PM EDT by KS_Physicist]
Most of the equipment I've had to work with here was personally signed by Faraday (read: OLD).

Sorry, I'm no help with your equipment. But if you hire me I'll be glad to look into it!

Jim

ETA: You might try emailing Fizassist, I think he's on a (self-imposed) break from Arfcom but would probably still receive the emails.
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