How to determine the Calibration/Test Weights with their classes

[Dongzkie]

I have 25 20kgs available Cast Iron Calibration/Test Weights and my problem is that i cannot find their documents it seems to be lost. I just want to know on what class this test weights belongs to, is there any possible ways on how to determined their classes?
Ex. Latest Calibration result
Nominal Value : 20kg Measured Value : 19.999kg Uncertainty +/-g : 0.0009k (k) : 1.96

Thank you

 

[howste]

I'm not an expert on weights, but I believe that cast iron weights of that size are generally not available better than Class F.

 

[BradM]

I'm not an expert on weights, but I believe that cast iron weights of that size are generally not available better than Class F.

I agree with this statement.

https://www.troemner.com/weights_classF_castiron.php

Is there a serial number/mfg. on the weights? If so, you might could figure out who made them and by the serial number, they might can tell you how they were made.

Otherwise, I would consider them Class F. If you have a history of the reported error of the weights, compare them to the tolerance charts to see if they are satisfactory.

All else fails, since you have a reported value (and a reported uncertainty), just assure your 20kg weights have sufficient accuracy for the work that you are doing. Do keep track of the values during each calibration. Keep an eye to assure there is no drift or anything.

Oh... and do keep the weights clean. It can make a difference.

 

[Dongzkie]

Thanks guys for the info.
This is the test that i have been using right now. There is no other identification available, i don't know what is NFA means.

 

[howste]

Thanks guys for the info.
This is the test that i have been using right now. There is no other identification available, i don't know what is NFA means.

I don't recognize NFA either. Hopefully it isn't Non-Functional Aspect. Maybe it's Not Fooling Around?

 

[Chance]

I was in that situation before...having test weights with no documentations whatsoever. I believe what you have is class F.
My suggestion for you is sending them to a calibration entity and have them calibrated for you. Hope this helps.