Agilent 3458 - Page 1
Forum section: electronics / general

author: echen1024
author_rank: Super Contributor
timestamp: February 21, 2014, 10:13:22 pm
content: Hi,I was have secured a few samples of Vishay HZ series ultra-precision resistors, and am about to build a very simple resistance calibration box. However, due to the accuracy of this, I would like some help in measuring the initial values. I was wondering if anyone here has an Agilent 3458 or similar class of DMM capable of measuring the 0.001% accuracy of these devices. I will ship it to you, and cover return shipping with USPS, as well as some compensation for your time. All I ask is the 8.5 digits returned to me in a email, PM, or even better, a photo.

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: February 21, 2014, 11:00:48 pm
content: What about asking the almighty dave to do it?

author: echen1024
author_rank: Super Contributor
timestamp: February 22, 2014, 01:07:42 am
content: Postage to Australia?

author: EEVblog
author_rank: Unknown
timestamp: February 22, 2014, 01:18:35 am
content: Quote from: TorqueRanger on February 21, 2014, 11:00:48 pmI don't have that class an instrument.

author: quarks
author_rank: Frequent Contributor
timestamp: February 22, 2014, 01:22:06 am
content: That sounds like a good idea. If you do not find anyone closer I will be happy to help.

author: dr.diesel
author_rank: Super Contributor
timestamp: February 22, 2014, 01:26:39 am
content: I have 7-1/2 (K2010), but it's not yet calibrated. Should have my replacement caps Monday, then off to Keithley for cal within a week or two.

author: AlfBaz
author_rank: Super Contributor
timestamp: February 22, 2014, 01:30:41 am
content: How expensive is it to just get a cal lab to do it?

author: robrenz
author_rank: Super Contributor
timestamp: February 22, 2014, 02:48:29 am
content: What resistances? The best the 3458A can do is .0013% of reading at 1k 10k and 100k it is much worse below and above that and below the top of each range.The Fluke 8508A is much better on resistance and yes I am comparing absolute cal values on both instruments.Neither of them gives a very good TUR for your .001%Fortunately someone who owns a 8508A has offered to help you

author: echen1024
author_rank: Super Contributor
timestamp: February 22, 2014, 03:47:05 am
content: Quote from: robrenz on February 22, 2014, 02:48:29 amFantastic! I will probably, in order to minimize the tempco, I might out it in a mineral oil enclosure as well a 4 terminals. When I am finished, I will send it toyou. We can discuss those details later.

author: Vgkid
author_rank: Super Contributor
timestamp: February 22, 2014, 05:46:54 am
content: You wouldnt need to enclose them in mineral oil, unless you plan on passing a good amount of current through them. Unless you really want to deal with properly sealing the enclosure, you will just need to keep them in a sealed box.

author: Dago
author_rank: Frequent Contributor
timestamp: February 22, 2014, 07:45:50 am
content: Quote from: AlfBaz on February 22, 2014, 01:30:41 amI have heard that calibrating Z-foils in an accredited lab (here in Finland) possibly including laser trimming (not sure) costs something ridiculous like 700€ per resistor. But you get a certificate for the resistor

author: TiN
author_rank: Super Contributor
timestamp: February 22, 2014, 08:56:08 am
content: Have calibrated KI 2400 and 2001, also 2002 which matches 2001 within ppmBut I'm in Taiwan, so USPS to here usually takes week or soHint for your design - embed temperature sensor (thermocouple or good RTD), so you can make suretemperature kept constant during measurements. Even while resistor itself is very stable -wiring, connectors, leads may not be so stable and generate thermal EMF's

author: robrenz
author_rank: Super Contributor
timestamp: February 22, 2014, 04:25:50 pm
content: Quote from: echen1024 on February 22, 2014, 03:47:05 amI am not the person with a 8508A

author: echen1024
author_rank: Super Contributor
timestamp: February 22, 2014, 05:30:24 pm
content: Would that be dr. diesel?

author: dr.diesel
author_rank: Super Contributor
timestamp: February 22, 2014, 05:32:42 pm
content: Quote from: echen1024 on February 22, 2014, 05:30:24 pmSorry, the best I could do for ya is the K2010@7-1/2 digits.

author: quarks
author_rank: Frequent Contributor
timestamp: February 22, 2014, 05:36:42 pm
content: robrenz, knows that I have a 8508A

author: echen1024
author_rank: Super Contributor
timestamp: February 22, 2014, 05:37:50 pm
content: Ahhh. Guess that I'll just pay the USPS price and ship it to you then.