Page 1 of 1

Measuring nanovolts DC with Keithley 2002

Posted: October 23rd, 2015, 8:57 am
by Heusler
Hello,

Is it possible to reliably measure nanovolts DC with Keithley 2002? According to its manual it has resoultion down to 1 nV.
However, on the lowest scale (200 mVDC) and integration time 10 PLC, slowly changing DC voltages about 10 ┬ÁV are measured quite noisy, signal-to-noise ratio is about 5%.
When the same line used for measuring with a different nanovoltmeter the measurements, are far less noisy, about 1%.

Re: Measuring nanovolts DC with Keithley 2002

Posted: October 23rd, 2015, 10:11 am
by brian.d.smith
You must be careful with microvolts that are thermally induced. You should use solid copper everywhere in your adapters and cables.

Shielding is required from the front panel of the 2002 all the way to your device.

Nanovoltmeters have these features built in.

Re: Measuring nanovolts DC with Keithley 2002

Posted: October 23rd, 2015, 4:29 pm
by Heusler
thank you for the answer!
But what is the real limit of this model?
What is the minimal signal-to-noise ratio at 10 nV, 100 nV, 1 mV DC signals?

Re: Measuring nanovolts DC with Keithley 2002

Posted: October 24th, 2015, 7:49 am
by brian.d.smith
Please see page 2 of the attached customer specification. RMS noise is specified as ppm.
SPEC-2002 (I - Nov 2009)(2).pdf
(237.6 KiB) Downloaded 1504 times