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Ion Chamber Connection to 487 -

200, 210, 220, 486/7, 60x, 61x, 64x Electrometers
409, 41x, 42x, 44x, 48x -
14x, 18x, 1801 Nanovoltmeters
15x, 18x Null Detectors/Microvoltmeters
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Joined: December 8th, 2016, 7:05 am
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Ion Chamber Connection to 487 -

Post by meesteph » December 8th, 2016, 7:18 am


I am currently in possession of a Keithley 487 - and an FC65-P ion chamber from IBA Dosimetry. The chamber needs to be biased to 500V to function, however the only connection out of the chamber itself the attached triax cable. What sort of connections/adapters would I need to simultaneously read current from this chamber and supply it with a 500V bias?

I recently found this image (below) of the connections required to do this on your 6517 electrometer, would the connections I need to make be the same?

Thank you for your time.
6517Connections.jpg (66.46 KiB) Viewed 10861 times

Andrea C
Keithley Applications
Keithley Applications
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Joined: October 15th, 2010, 10:35 am
Country: United States

Re: Ion Chamber Connection to 487 -

Post by Andrea C » December 9th, 2016, 10:07 am

In the image, the DC voltage supply LO is tied to chassis ground. The LO of the current meter is tied to the HI of the DC voltage supply.
In the triax connector, the current meter HI is the center pin; the current meter LO is inner shield....which will be at DC voltage supply potential.

NOTE: the interlock is shown as bypassed/defeated. This is unsafe.

Below is an image from the Low Level Measurements Handbook.
You can obtain a copy from here:
http://www.tek.com/search/apachesolr_se ... andbook%22
IonBeam_TriaxConnector.PNG (18.64 KiB) Viewed 10852 times

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