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Rocks and Buckets

by Paul Floyd, LDAF Director of Weights and Measures

I say all the time that we, as Weights and Measures inspectors, put rocks on scales and fill up buckets. What an easy job! In a very over-simplified way, that is what we do.

We do know exactly how much the rock (mass standard) weighs and how much liquid the bucket (field standard or prover) will deliver under very specific test procedures. When we put standards on a scale or fill a prover, are we inspecting the device? If you answered yes, congratulations, you just got homework! Reread Handbook 44. Appendix A. Fundamental Considerations (specifically section 4.1. Inspection Versus Testing.)

This section makes the argument that putting weights on a scale should not be considered inspecting the device but should be considered testing the device. The inspection part of checking a scale should be determining if the device meets the specifications, suitability, maintenance, and user requirements listed in HB44. The testing part can be described as determining “the accuracy of value or performance of the equipment under examination by comparison with the actual physical standards of the official.” What a mouthful…”putting rocks on scales” is way easier to say!

The simple scale above would probably pass the testing but not the inspection of the device. That leads us deeper into Fundamental Considerations, specifically, section 4.7…that section you will have to research on your own. Yep, now you all have homework! Thanks for participating in National Weights and Measures Week!