How to check Rigol DP832's accuracy - Page 1
Forum section: electronics / testgear

author: SHARANYA
author_rank: Contributor
timestamp: January 22, 2018, 08:04:17 pm
content: Dear expertsI am a little bit confused about which formula to use for the accuracy checking of the Rigol DP832's voltage & current.In the datasheet,there is a column "Annual accuracy" for programming & readback.Also there is a column which states the "Stability".So my question,for say,I have setted 5v & my DMM reading is 5.001v.So should I calculate using the formula mentioned in the Annual accuracy>programming(.05%+10mV) or should I calculate using the Stability(.02%+2mv)??Please help!!

author: JDubU
author_rank: Frequent Contributor
timestamp: January 23, 2018, 04:04:01 pm
content: The annual accuracy is the maximum variation from calibrated output values after one year from the time of calibration.Stability is the maximum variation of output values over an 8 hour time period (from datasheet: "Note: The variation of the output within 8 hours after 30-minute warm-up when the load circuit and environment temperature are constant."). So stability is a shorter term variation within the constraints of the annual accuracy.

author: SHARANYA
author_rank: Contributor
timestamp: January 23, 2018, 06:00:39 pm
content: Thanks a lot for the nice explanation.My unit has not completed one year yet.In july-15,2018 one year will be completed after calibration.So i should stick to the "Stability" then!Am i correct?

author: JDubU
author_rank: Frequent Contributor
timestamp: January 23, 2018, 06:58:31 pm
content: The stability specification only guarantees that the outputs will not change by a certain amount over an 8 hour period with a constant load and environment. It does not say anything about absolute accuracy.Absolute accuracy is determined by comparing the output of the power supply to some external calibration standard. The one year accuracy spec for the power supply says it won't deviate by more than a certain amount for one year from the last calibration.If you are concerned about the absolute accuracy of the power supply, you can use a more precise instrument to monitor the output and adjust the power supply using those readings as you go or, use that instrument to adjust the internal calibration of the power supply as often as you want. The Rigol calibration guide for the DP800 series power supplies is attached below. To do the calibration, you would need a DMM that has the accuracy that you want. A 6 1/2 digit bench DMM is recommended, but you could even use one of the very inexpensive Chinese 10,000 count DMM's (e.g.https://www.banggood.com/search/an8009.html) and use that as your calibration standard. This would get all of the channels of the power supply to have a consistent calibration but would only have the absolute accuracy of the DMM you are using as your standard. It's all relative. It depends on what you need the power supply to do for you.

author: Simon
author_rank: Unknown
timestamp: September 30, 2018, 02:41:04 pm
content: Quote from: Wolfgang on September 30, 2018, 01:01:36 pmerm and you are who exactly? you seem to be posting this all over the forum, if this is so desperate and valuable to everyone why don't you contact us and lay you case out?

author: Wolfgang
author_rank: Super Contributor
timestamp: September 30, 2018, 02:43:25 pm
content: What I am is in my profile and website.https://electronicprojectsforfun.wordpress.com/Whats driving me is just curiosity, no commercial interests. Is a popular thing, there has been a lot of debate, and I just wanted to know how owners feel about it, nothing else.I have no hidden agenda.

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 30, 2018, 02:45:54 pm
content: Quote from: Wolfgang on September 30, 2018, 02:43:25 pmStill, posting the same message 8 times is a bit how-you-doing…

author: Wolfgang
author_rank: Super Contributor
timestamp: September 30, 2018, 02:48:46 pm
content: The reason to do that was to generate some awareness for the poll in threads related to the subject.I could not see whats wrong with that.

author: glarsson
author_rank: Frequent Contributor
timestamp: September 30, 2018, 02:53:13 pm
content: What happens if everyone posts all over the forum because they feel important? Spammer!

author: Wolfgang
author_rank: Super Contributor
timestamp: September 30, 2018, 02:54:58 pm
content: ... its not "all over the forum". I did it *only* in threads related to the DP832.

author: glarsson
author_rank: Frequent Contributor
timestamp: September 30, 2018, 03:20:04 pm
content: Doesn't matter.

author: Simon
author_rank: Unknown
timestamp: September 30, 2018, 03:22:08 pm
content: Quote from: Wolfgang on September 30, 2018, 02:48:46 pmAnd if it is such a worthwhile cause simply contact me and I could make your poll a sticky, as you can see instead you are just annoying everyone with spammer like behaviour. You could also put a link in you signature (and then not make posts simply for the sake of it).

author: Wolfgang
author_rank: Super Contributor
timestamp: September 30, 2018, 03:29:53 pm
content: Sorry, I did not know how to make this "sticky".What is the official way to get something sticky ?BTW: I just had *one* compliant so far.

author: Simon
author_rank: Unknown
timestamp: September 30, 2018, 03:56:04 pm
content: Quote from: Wolfgang on September 30, 2018, 03:29:53 pmYou can'tQuoteYou ask a moderatorQuoteYou have had one complaint? I don't care how many complaints you have had. I have had several reports and i am getting fed up.As a general rule, think, "if everyone did what I am doing what would happen?". If everyone pasted such messages it would lead to chaos, if everyone wants everyone else to tell them what they think of such and such equipment it would also lead to chaos.

author: Wolfgang
author_rank: Super Contributor
timestamp: September 30, 2018, 04:01:57 pm
content: OK then, I wont do it again.Would you please make this "sticky" ? Your profile shows you are a moderator.

author: bson
author_rank: Unknown
timestamp: October 01, 2018, 10:22:15 pm
content: If you have a bench DMM with GPIB/LXI then just recalibrate your DP832 yourself when you suspect it has drifted, or when the readbacks differ from the setpoints. If you search you'll find the various calibration scripts created for this purpose in the past. It's a PSU, not a precision DMM, and can be calibrated with just about any 5.5 digit bench DMM.In two years since calibration the readback on mine is still within 1mV/1mA, and similarly for setpoints. IMO that's perfectly fine stability and excellent precision for a PSU, but maybe your needs exceed mine.