回复： Is my multimeter NI USB-4065 produced earlier or pirated?

[kirsch]

To self-calibrate a board using NI-DMM, all you need to do is:

1. initialize a session
2. call Self Cal
3. close the session

Be aware that your board's external calibration is expired, so running self cal will not get it to specification, and may or may not succeed at all. I suspect you will get the same error you got in MAX. I recommend you find a service to perform external calibration on your instrument.

[NanWang]

Does each USB-4065 have to self-calibrate within a year, otherwise it can only be externally calibrated when it expires, and the device will gradually become inaccurate? Thank you for your reply.

[kirsch]

No. To be within specs the DMM needs to be externally calibrated before the calibration expires. Self calibration is recommended to be run more frequently, I believe daily. And the board should be warmed up when you run it by powering it up for a while.

More info:

https://www.ni.com/pdf/manuals/376812a.pdf

[NanWang]

How to calibrate externally? Is there any organization? I am in China.

[santo_13]

As per this link https://www.ni.com/en-us/shop/services/hardware/calibration-services/service-centers.html , there is a calibration centre in China

NI China

2nd Floor, Building 2, No. 400 Fangchun Road, Pudong New District
Shanghai, China 201203
 

Certificate Number 3237.01

NI Certified Calibration Center China

Operated by Micro Precision Calibration Inc.
1505~1506 Building #3D
Tian'an Cloud Park, Phase I

2018 Xuegang Road,
Bantian, Longgang, Shenzhen, GD 518129
China