HP 3457a calibration report question - Page 1
Forum section: electronics / general

author: rounin
author_rank: Regular Contributor
timestamp: December 14, 2016, 03:28:34 am
content: I've been starting to get into building a daq / daq frontend, and so to test the accuracy I decided to get a precision bench meter off ebay (HP 3457a), and then since I needed to know if it still worked (looks like ~1985 vintage, I replaced the sram battery but nothing else), decided to get it calibrated.It looks pretty good to me, at least for the low VDC and ADC ranges I need.But - it looks like they only recorded 4-5 digits on the calibration measured values for some values - is it normal? I was thinking they would do all 6 digits. Maybe they just truncated the zeros?Thanks,rounin

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: December 14, 2016, 03:59:47 am
content: Congratulations on your purchase. I like the 3457A since it is quiet and has the lower DC ranges.Did the cal cert list the equipment used to calibrate it? Some of the readings end in zero so I it's likely the readings are missing data.Also, the performance tests require a short on the DCV ranges and it appears this data was not collected among others.The document looks a little fishy to me compared to the ones I have received.I would contact them for more info and ask them why the full performance test was not done as per the service manual.Thanks for sharing.

author: rounin
author_rank: Regular Contributor
timestamp: December 14, 2016, 04:05:01 am
content: I cropped the full report, they used a Fluke 5520A. I'll re-read the service manual and ask them - maybe this is why the lab was 1/2 the price of keysight, oh well.

author: Krytron
author_rank: Contributor
timestamp: December 14, 2016, 04:14:44 am
content: I attached a copy of the cal report did on mine a while back. Just the data, as the other sheets had personal info and another was the calibrator info which was a fluke 5700A/5725A.

author: rounin
author_rank: Regular Contributor
timestamp: December 14, 2016, 04:30:28 am
content: Thanks Kryton that helped a lot. I just sent the lab an email, we'll see what they have to say...

author: rounin
author_rank: Regular Contributor
timestamp: December 15, 2016, 02:48:13 am
content: Apparently the low-ish price I payed was just for a pass/fail spec test, they have the data logged but don't provide it. It sounds like they might not record full precision in this case. They are going to redo it for me though and are paying for the shipping, which is nice of them. I'm not sure if anyone noticed the 9.99999V reading on the 1V test on the report, they were a bit apologetic about that : ). Apparently this form is auto-generated from their auto-cal test rig data, and it slipped a digit somewhere....

author: cncjerry
author_rank: Unknown
timestamp: January 09, 2017, 06:04:05 am
content: Can you guys recommend a place for calibration/adjustment? Prefer the SF bay area, definitely in the US, for one of my 3457A meters?Also, can you comment or send me a PM on how much to expect to pay?Thanks.

author: Tony_G
author_rank: Super Contributor
timestamp: January 09, 2017, 07:03:12 am
content: Keysight will charge $210. I'd save up and have them do it.TonyG

author: Krytron
author_rank: Contributor
timestamp: January 10, 2017, 05:40:45 am
content: Quote from: Tony_G on January 09, 2017, 07:03:12 amKeysight offers several levels of calibration. The first type is basic pass/fail, the only certificate you get, states your meter is in tolerance. The second level of calibration, the measurements are recorded and presented to you, and no adjustments are made to the unit. . The third level of calibration is when they adjust the unit so the meter does not display any error (or minimal error/best effort), and you receive before and after data. The third level was quoted to me for just under $500 with shipping from Loveland.I also requested that Keysight replace the battery before the calibration began. They refused saying they no longer service these units. As the battery holds up the memory that holds the calibration constants and corrections and these units are old - they need to be replaced before the battery fails.

author: Tony_G
author_rank: Super Contributor
timestamp: January 10, 2017, 08:15:45 am
content: Interesting, I've only had them do my 3458A and my 11722A power sensor. I got full data both times and I picked the lowest level.That $210 price is supposed to give you:R-50C-511: Keysight CalibrationTests all product specifications using manufacturer-developed procedures and softwareIncludes certificate and full measurement reportIncludes all adjustments and as-received data for any out-of-tolerance instrumentComplies with ISO 9001:2008Displayed price is total for one calibrationThere must be more too it for them to quote you that. Maybe it had something to do with the repair (aka battery replacement) - I do have to say that they go out of their way to may the agreement/per incident/level things confusing.In general though, I really feel that paying the extra for a manufacturer calibration is worth it.TonyG