Tolerances for Analytical Balances

[Raulinho]

Hi,
We currently purchase Class 0 weights to verify our analytical balances which display up to 4 decimal places. We are trying to ascertain which tolerances to use while verifying them since the values given on the traceable weights certificate (derived from ASTM E617) are extremely stringent to 6 decimal places. What do you all use as a guide to verifying balances since we do not have a recognized National Metrological Institute where we live and the cost is extremely high for calibrating weights/balances overseas.

 

[dwperron]

Hi,
We currently purchase Class 0 weights to verify our analytical balances which display up to 4 decimal places. We are trying to ascertain which tolerances to use while verifying them since the values given on the traceable weights certificate (derived from ASTM E617) are extremely stringent to 6 decimal places. What do you all use as a guide to verifying balances since we do not have a recognized National Metrological Institute where we live and the cost is extremely high for calibrating weights/balances overseas.

The manual that comes with the balance will have the guaranteed specifications listed. Typically these will include repeatability and linearity, sometimes minimum weight.

 

[Johanna]

The manual that comes with the balance will have the guaranteed specifications listed. Typically these will include repeatability and linearity, sometimes minimum weight.

Those generally do not take the uncertainty of the used weights into account.

Hi,
we do not have a recognized National Metrological Institute where we live and the cost is extremely high for calibrating weights/balances overseas.

What is the cost if the weighing tasks are no longer traceable and the scales are out of tolerance for the product you are selling?

 

[BradM]

Hello there!

My apologies for my lack of understanding. Are you asking about the tolerances for the weight set, the balances, or both?

Do you have any industry regulatory mandates?