Keithley 2182A Digital Nanovoltmeter - Page 1
Forum section: electronics / testgear

author: Terabyte2007
author_rank: Frequent Contributor
timestamp: October 21, 2013, 03:09:25 pm
content: Does anyone have any experience with the Keithley 2182A Digital Nanovoltmeter? Is it worth the 3K price tag?http://www.keithley.com/products/dcac/sensitive/lowvoltage/?mn=2182A

author: robrenz
author_rank: Super Contributor
timestamp: October 21, 2013, 04:02:58 pm
content: The Agilent 34420A nanovoltmeter/micro ohmmeter has a built in current source so it can do resistance without a separate current source but it costs a little more. I don't know which one has better specs for voltage.

author: branadic
author_rank: Super Contributor
timestamp: May 10, 2018, 09:40:59 pm
content: Even though this thread is very old, yes it seems to be worth it's price. We have one at work and I have checked relative zero over 2h using the internal RS232 interface with a selfmade short. Both filters analog and digital are active, NPLC is 5. I have never seen Attovolt coming through an USB interface before.-branadic-

author: Alex Nikitin
author_rank: Super Contributor
timestamp: May 11, 2018, 12:32:28 pm
content: Quote from: branadic on May 10, 2018, 09:40:59 pmHow does it compare with the K181?CheersAlex

author: Terabyte2007
author_rank: Frequent Contributor
timestamp: May 11, 2018, 12:54:16 pm
content: Quote from: branadic on May 10, 2018, 09:40:59 pmNice, I am afraid my lab may have too much background interference to accurately measure that low. I would need to build a shielded enclosure. I have a high resistance meter that will measure well into the TerraOhms but I have to use it with my DUT in a grounded aluminum box. Thanks for the info!

author: branadic
author_rank: Super Contributor
timestamp: May 11, 2018, 02:42:13 pm
content: QuoteCan't tell you that, as I never recorded 2h data with Keithley 181, but you can get a raw idea of Keithley 181 performance in this video:https://xdevs.com/cm/RandomPics/K181_Cable/20171009_194206.mp4-branadic-

author: kj7e
author_rank: Frequent Contributor
timestamp: May 11, 2018, 03:17:03 pm
content: Quote from: branadic on May 11, 2018, 02:42:13 pmLooks like a CalMachine video. Damn, now I want one and I don't even have a use for it.

author: branadic
author_rank: Super Contributor
timestamp: May 12, 2018, 08:49:34 am
content: It is a CalMachine videoThis piece of kit is really nice, but I'm lacking applications for it beside monitoring the difference between voltage references. Thus, I sold my Keithley 181 and if needed can use the 2182A we have at work.The nice thing about 2182A is that it has 2 channels, even though the second channel has only 10nV resolution and a maximum input voltage of 12V. Good enough for ratiometric measurements like characterizing voltage dividers without necessarily rearranging probe tips.-branadic-

author: TiN
author_rank: Super Contributor
timestamp: May 13, 2018, 03:40:29 am
content: I can part with 182M as I got 2182A as repair project already

author: kj7e
author_rank: Frequent Contributor
timestamp: May 13, 2018, 03:56:32 am
content: Quote from: TiN on May 13, 2018, 03:40:29 amYou have the fancy connector for it? The 182 may be more than I'm willing to spend.

author: TiN
author_rank: Super Contributor
timestamp: May 13, 2018, 04:02:31 am
content: Yup, complete kit. I even have Keithley 1488 short.I recalibrated it a week ago, using 5700A/3458A.

author: kj7e
author_rank: Frequent Contributor
timestamp: May 13, 2018, 04:30:17 am
content: Send me a PM with the info.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: May 14, 2018, 08:56:25 am
content: Quote from: branadic on May 11, 2018, 02:42:13 pmHere is the result from my Keithley 181 over 5.5 hours - offset compensated, with +/-95nV input voltage applied for some of the time. Recorded by the K34465A at 1sec intervals from the analogue output, vertical scale is in microvolts.CheersAlex

author: branadic
author_rank: Super Contributor
timestamp: May 16, 2018, 06:58:41 pm
content: QuoteThanks for the plot. Is there any difference in noise using digital data via GPIB or analog output plus a voltmeter? How did you manage to generate those 95nV?-branadic-

author: Alex Nikitin
author_rank: Super Contributor
timestamp: May 16, 2018, 09:13:33 pm
content: Quote from: branadic on May 16, 2018, 06:58:41 pm1) No difference. The (isolated) analogue output is generated by a 12-bit DAC, either from the top or from the bottom 3.5 digits. Each step is 1mV and clearly visible on a good meter, like the 34465A on 100mV or 1V range, so 1mV on the output from the bottom end = 1LSB = 1nV input on 2mV range.2) From a divider - 21M/10R (just an accidental value) mounted in the plug and connected to 200mV output from the Keithley 617. 10 ohm in the divider is probably adding to the noise/drift as it is a simple 1% metal film resistor. I will re-build it with better resistors - probably a metal foil 10R, and a good quality 10M for 1/1000000 divider.CheersAlex

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: May 17, 2018, 01:25:45 am
content: Cool data. I happen to be playing with the HP 34420A and will record similar data. Let's have a shootout of nanovoltmeters.

author: TiN
author_rank: Super Contributor
timestamp: May 17, 2018, 04:55:07 am
content: Mod then should rename the thread then

author: Alex Nikitin
author_rank: Super Contributor
timestamp: May 17, 2018, 08:51:18 am
content: Quote from: TiN on May 17, 2018, 04:55:07 amPerhaps it would be better tostart a separate thread.CheersAlex