Author Topic: How to check Rigol DP832's accuracy  (Read 288 times)

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Offline SHARANYA

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How to check Rigol DP832's accuracy
« on: January 23, 2018, 07:04:17 AM »
Dear experts
I 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!!
 

Offline JDubU

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Re: How to check Rigol DP832's accuracy
« Reply #1 on: January 24, 2018, 03:04:01 AM »
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[3]: 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.
« Last Edit: January 24, 2018, 03:07:09 AM by JDubU »
 

Offline SHARANYA

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Re: How to check Rigol DP832's accuracy
« Reply #2 on: January 24, 2018, 05:00:39 AM »
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?
 
 

Offline JDubU

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Re: How to check Rigol DP832's accuracy
« Reply #3 on: January 24, 2018, 05:58:31 AM »
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.
« Last Edit: January 24, 2018, 06:32:35 AM by JDubU »
 


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