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EEVblog => Other Blogs => Topic started by: Circuitous on July 01, 2015, 11:51:35 pm

Title: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: Circuitous on July 01, 2015, 11:51:35 pm
New to the lab is this Keithley DMM7510, a 7 1/2 digit, high performance meter.  This beast is amazing!
Here I take a first look at the meter and run a few measurements.

No teardown, since I paid for it!
DMM7510 (https://www.youtube.com/watch?v=MY1CcSFeJnE)
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: HighVoltage on July 02, 2015, 06:45:08 am
Great first impression Video, Thank you !

Do you have a stable voltage standard and could see the drift of the 7510 over 24 hours
Would be interesting to see the graph for that.
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: HKJ on July 02, 2015, 10:00:56 am
You need something very stable to see the drift of them 7510.
I compared it to a couple of other meters with a cheap voltage standard:
(http://lygte-info.dk/pic/cpf3/DMM%20compare12hoursSmooth5min.png)

Reference used:
(http://lygte-info.dk/pic/Equipment/DSC_6720.jpg)
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: Circuitous on July 09, 2015, 02:27:14 am
I finally ran a successful 24 hour test, I'll try to do a longer one some time.

(https://corgitronics.files.wordpress.com/2015/07/10v-24hour_graph.png)

And, here's the setup.  If you see anything to improve the tests, please let me know.

Stability test (https://www.youtube.com/watch?v=49zqxbAAz2E)
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: Jay_Diddy_B on July 09, 2015, 04:00:46 am
Hi,

You might want to look at using special low thermal emf leads. There is a thread here:

https://www.eevblog.com/forum/buysellwanted/diy-low-emf-cable-and-connectors/ (https://www.eevblog.com/forum/buysellwanted/diy-low-emf-cable-and-connectors/)

I use Pomona low thermal emf leads with my Datron 1281.

Regards,

Jay_Diddy_B
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: HighVoltage on July 09, 2015, 08:02:03 am
I finally ran a successful 24 hour test, I'll try to do a longer one some time.
Thank you!
Very nice, to test it with a SVR-T from Geller.
I have exactly the same Geller voltage reference, so this can be a good comparison to my Keysight 34470A .

What I would like to see is the same test with 100 NPLC setting of the 7510 over 24 hours,
and the range manually set to 10 V, if you can.
Could you also save the data to a csv or excel file?

Quote
And, here's the setup.  If you see anything to improve the tests, please let me know.
What I noticed in my test's is to keep all RF transmitter and receiver (WiFi, Cell-Phones) far away from the test setup.
Otherwise, was was said already: special low thermal emf leads might be a good investment.

Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: Andreas on July 09, 2015, 09:02:56 pm
Could you also save the data to a csv or excel file?

+1 .csv or .txt preferred.

Perhaps you can put a cloth over the setup to prevent air currents from creating thermal noise.

With best regards

Andreas
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: HighVoltage on July 11, 2015, 09:22:44 am
Recently I tested my Geller Labs SVR-T with 3 Agilent meters at the same time in parallel:
2 x Agilent 34461A
1 x Agilent 34470A

Here are the results in comparison after a 4h test.
Manual setting to 10V range
100 NPLC

I am mostly surprised about the small spikes during the test, although everything was far away from any known RF disturbance.

(https://www.eevblog.com/forum/other-blog-specific/trying-out-my-new-keithley-dmm7510-a-7-5-digit-beast/?action=dlattach;attach=160682;image)
First Agilent 34461A

(https://www.eevblog.com/forum/other-blog-specific/trying-out-my-new-keithley-dmm7510-a-7-5-digit-beast/?action=dlattach;attach=160684;image)
Second Agilent 34461A

(https://www.eevblog.com/forum/other-blog-specific/trying-out-my-new-keithley-dmm7510-a-7-5-digit-beast/?action=dlattach;attach=160686;image)
Agilent 34470A

What I really like about your DMM7510 is that fact, that the standard deviation is shown in its nice units of nV instead of so many zeros. The DMM7510 seems to be a really amazing meter. May be you can produce a few more videos, showing the use of that meter.


 
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: Vgkid on July 11, 2015, 03:18:59 pm
Thanks for that video.
Title: Re: Trying out my new Keithley DMM7510, a 7.5 digit beast
Post by: Circuitous on July 12, 2015, 03:27:37 am
What I really like about your DMM7510 is that fact, that the standard deviation is shown in its nice units of nV instead of so many zeros. The DMM7510 seems to be a really amazing meter. May be you can produce a few more videos, showing the use of that meter.

There will definitely be more videos, enough to bore everyone.
Thank you all for the feedback.  I'll get some low thermal EMF leads, and do another test when I can.  I'll be getting back to some of my low-power measurements, which is why I bought this meter.  I look forward to more critiques.

Meanwhile, back to work (day job, every day).