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Sciencemadness Discussion Board » Engineering and Equipment » Reagents and Apparatus Acquisition » Picoammeter

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hector_carbossa

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posted on 13-1-2009 at 14:39

Picoammeter

Hi,

today I found this instruments. It seems a small pc tower, has red 7 lines display, various ports on rear and various regulations.
"Input" port seems to be gold plated coaxial SMA connector but I'm not sure. This time I'm not sure about nothing.
Someone knows this stuff? What's minimum setup? Which probe I've to use?

I haven't taken it yet for reason I imagine have not to explain.
Probably I dreamt may be useful measuring 10^-12 A currents, so I thought I may use normal TV coaxial cable as probe (high voltage seems main reason for those cables usage).

But as I stated this is dreaming thought

What do you think/know about?

densest

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posted on 19-1-2009 at 09:52

Can you post some pictures? Or some of the text like a manufacturer's name and model number, the labels on the displays, etc.

A picoammeter usually uses Teflon/PTFE insulated cable for low leakage. The connector will give some clues: if it has contacts for two coaxial (concentric) shields, it would require a special probe and cable - the inner shield is called a "guard" and it is driven by an amplifier from the signal in order to reduce the leakage from the signal wire.

hector_carbossa

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posted on 20-1-2009 at 23:05

Hi.
Here some pictures. In truth, I've found an half solution, so, I powered on this old equipment with nixie tubes. As probe, truncated coaxial cable seems to work well, measuring 5 uA on analog display for a exhaust 1 V button battery (but I have to do better tests with some known resistors).

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