Uncertainties versus 4 to 1 tar

[joecalibratio]

Pardon if this has been addressed.

As a manufacturer of measurement equipment, if we can claim a 4 to 1 accuracy ratio (or greater) do we need to create an uncertainty budget?
The way I understand it is that we only need to determine our uncertainties if we cannot meet the 4/1.

Thanks for all the help on this forum. Your patience and expertise is invaluable. (for this I am certain) Joel

[Hershal]

The answer to your question lies in whether you are or will seek accreditation.

Under the American National Standard ANSI/NCSL Z540-1-1994 (a self-declared standard) an uncertainty budget is not required. Understand this puts your customers in an undesirable situation as they will not have the uncertainties required for their calculations.

If you are seeking or will seek accreditation (certainly suggested if you build measuring equipment), or are already accredited, then the answer is yes, you must have the uncertainty budget.

If you are not yet accredited but will seek it, remember there are three bodies in the U.S. that are internationally recognized: IAS, A2LA, and NVLAP.

Hope this helps.

Hershal