Is this thing working? Why NIST calibration standards are important.
Tuesday, June 7, 2016
Have you ever weighed yourself on two separate scales with differing results? Some of you may shrug it off, forgive the least flattering result and go about your day. This however, is not a luxury and certainly not a standard for you who depend on the reliability of your test and measurement equipment.
So, how can you be sure that our scales, gas testers, thermometers, clocks, and calibrators are delivering precise measurements? What is our basis for determining a single pound, one volt, or one second in time? Who can uphold and certify this standard impartially?
Well, at the turn of the twentieth century, Lyman Judson Gage, the 42nd Secretary of the Treasury, asked the same. He wrote a letter to the House committee on Coinage, Weights, and Measures requesting that an institution be set up for national standardization. The committee unanimously supported it and in less than a year a bill passed establishing the National Bureau of Standards. Ironically, it was an act of Congress important enough to defy the idiom. This could not have come at a better time as innovation, science, and industry were in a new golden age, and America’s exports were becoming commonplace in foreign markets.
Today, NIST, the National Institute of Standards and Technology, is that very non-regulatory government agency tasked to keep the measurement standard. Their work not only gives us a standard to certify the accuracy of our measurements, they also strive to improve on the very standard itself. In 2014 alone, NIST rolled out a new atomic clock that is so accurate it will not waver by so much as one second in 300 million years’ time.
Steve Jefferts, a NIST Physicist who worked on the atomic clock, says, “The job of NIST is to recognize and bring forward the best standards you can have for basic quantities of length, mass, time and things like that. Presumably you end up pushing as hard as you can to build the best standard you can… When you make it better somebody starts having a use for it so you have to make a better one and this process continues to this day.”
Certainty of measurement is obviously very important, calibrating your test and measurement equipment should then be equally as obvious. It is recommended that test and measurement equipment be calibrated yearly to ensure its reliability. Most manufacturers will offer factory spec calibration, but NIST being the recognized standard represents added value and certainty to this calibration. Here at Extech, we offer a sizeable listing of calibrated products with certificates traceable to NIST and perform calibrations on older meters in-house.
A reliable instrument gives consistently accurate measurements and consistently accurate measurements are what make you successful on the job and credible in your field. Then again, perhaps the bathroom scale can remain purposefully ambiguous.