Calibration Accuracy/Tolerance

[Calibrationian]

Hello Sirs,

I am a bit confused with this specification of an LCR Meter.

At the very Manual this was stated.

"If the measurement values are within the range stated below, it is approximately correct. Calibration value of standard ±(Calibration accuracy of standard + accuracy of ZM2371 / ZM2372) "

Later on below was this statement.

" Measurement accuracy  Basic accuracy 0.08%"

which must be the specification used in the calibration certificate to declare its tolerance Limit?

I hope someone can help me... Thanks...

 

[dwperron]

Hello Sirs,

I am a bit confused with this specification of an LCR Meter.

At the very Manual this was stated.

"If the measurement values are within the range stated below, it is approximately correct. Calibration value of standard ±(Calibration accuracy of standard + accuracy of ZM2371 / ZM2372) "

Later on below was this statement.

" Measurement accuracy  Basic accuracy 0.08%"

which must be the specification used in the calibration certificate to declare its tolerance Limit?

I hope someone can help me... Thanks...

Can you supply the manufacturer and model of this meter so we can look at the full set of specs.

 

[Calibrationian]

Can you supply the manufacturer and model of this meter so we can look at the full set of specs.

Manufacturer: NF
Model: ZM2372
It's a Japanese Brand of LCR Meter, which makes it more confusing since it's calibration certificate are all in Japanese...

 

[ChrisM]

Is there a National or International Standard against which the "calibration certificate" has been issued?

From memory, for example, the accuracy of capacitance measurement varies depending on the frequency of the ac signal used to calculate it

 

[dwperron]

If you go to the NF website you will find that the Manual and the Specification sheet are both available in English.
The 0.08% Basic Accuracy is the absolute best case accuracy. It only applies to impedances of 100Ω to 100kΩ at 1 kHz.
I give the manufacturer credit for including the data to account for the sources of error that you may encounter, and the formula that you can use to calculate the measurement accuracy using the terms presented in their specifications:
Az = ( A ＋ B × U ＋ Kz ＋ Ky) × V × KT ＋ KB × U
All the terms are defined on their spec sheet. Some of the terms are insignificant, but they are available if you need them.
I've dealt with some specifications like these in RF gear and power analyzers. If you need to come up with the accuracy for a specific measurement then use the formula. Most places will be using these over a limited range of measurements. Make a table of the calculated accuracy values for your purposes and keep that handy.