Back to Ganoksin | FAQ | Contact

Gem scale standardization


#1
    My day job involves use of various pieces of technical
analytical equipment. We routinely standardize the equipment to
verify accuracy, and make adjustments to restore accurate
measurement. How does the Orchid group approach standardization of
scales? 	Thanks ever so, Judy in Kansas 

Judy: I didn’t worry about it when I was using the small “pocket” gem
scales that typically read to +/- .1 or .05 carat. I just
periodically calibrated the scale with the calibration weight that
comes with it. However, when I finally got a millicarat scale (used
Sartorius electronic lab balance, from Ebay), I bought a certified
standard test mass, and use that for calibration. The test mass has
to be re-certified periodically by the manufacturer, as well. I’m
sure you are aware of this, but for the rest of the group, these
standards come in various grades – if you buy one, you want to get
one such that the weight tolerance range is better than the
repeatable accuracy figure of your scale, so it does not introduce
additional error. I think the one I bought (50 gram) was about $85.

Now I am fairly confident that someone isn’t going to come back to
me and be able to sue successfully that a diamond I sold them was
misrepresented as to weight, as I can trace my scale’s accuracty via
written calibration records back to the NIST standards.

Regards,
Bob Edwards
Chromis Designs