Lesser expensive to calibrate various test weights

[Dongzkie]

I have 25 20kg in our lab, they were all calibrated annually.
my question is, can I only request 1 20kg to be calibrated this will be my working standard then I will do the verification for the remaining 24 test weights? because I have here available scale w/c can be use to verify those remaining test weights.
is this acceptable?

 

[Jen Kirley]

Good day Dongzkie,

I am wondering what are your tolerances? Secondly, what discrimination do your scales detect? Standards - including transfer standards - are often calibrated to an accuracy notable in discrimination x10 that of the instrument they are used to verify. As an example, the scale measures in 10ths and the test weight is calibrated to accuracy in hundredths. Unless your scales measure at a larger discrimination than the test weights are calibrated to, I would not agree to use them to verify test weight accuracy.

I hope this makes sense!

If costs are a very great concern you might question whether you need 25 of these test weights. Could you manage with fewer of them?

 

[Dongzkie]

Jennifer,
we use 0.5kg resolution on our process. we use bench scale on the production 150kg capacity and 1 500kg floorscale. As for example I have 1 20kg calibrated result is 20.000kg As found and has a uncertainty of +/-0.001kg. I have some available scale here which i can be use, and i can set this scale to 0.001kg readability, what if when I weigh the 20kg test weight to that scale and reads correctly to 20.000kg, is it okay to use that scale to verify the other 24 20kg test weights? thank you

Good day Dongzkie,

I am wondering what are your tolerances? Secondly, what discrimination do your scales detect? Standards - including transfer standards - are often calibrated to an accuracy notable in discrimination x10 that of the instrument they are used to verify. As an example, the scale measures in 10ths and the test weight is calibrated to accuracy in hundredths. Unless your scales measure at a larger discrimination than the test weights are calibrated to, I would not agree to use them to verify test weight accuracy.

I hope this makes sense!

If costs are a very great concern you might question whether you need 25 of these test weights. Could you manage with fewer of them?

 

[somashekar]

Weighing scales could be governed by statutory requirement by your government bureau of weights and measures. Please also check with them for calibration requirements.

Read more HERE and find your relevance.....

 

[Hershal]

In theory yes. But to do a proper job of calibrating the other weights, you should understand the effects of local acceleration of gravity, temperature, essentricity, altitude compared to the external lab, and then these and other factors must be considered in your uncertainty calculations, so that you know whether the other weights actually meet your needs.

 

[Jeff Frost]

A good question at this point is what has your review of all past calibration reports indicated. If the weights are not changing between annual calibration interval why are you not extending the calibration cycle? Your calibration system should have a method to extend or reduce calibration cycle based on results of calibrations.