ppm of reading

[AsadAA]

Dear All,

I have problem understanding specification of my PXI 4072 card. On the specification data sheet its written accuracy is DC Current +/- (PPM of reading + PPM of range) , what does this PPM of reading means ?

Best Regards

[K C · Accepted solution]

Hi,

I would like to say: 'Why use it if you don't understand it'  But I don't know your situation.

How I understand it: For DC current as in your picture the tolerance 2 years after calibration is 500ppm of the reading + 50ppm of the range for the 1A range.

So if your are measuring 500mA the tolerance is (500ppm of 500mA) 250 µA + (50ppm of 1A) 50 µA = 300 µA 

Kees

[AsadAA]

need that parameter to calculate the measurement uncertanity of the card. Thanks