Putting Certainty back into Uncertainty

Description

Every day thousands of observations are recorded by ARM instruments, analyzed and archived, but how confident are we of those measurements? A first approach was to harmonize expression of measurement uncertainty for all ARM instruments. Nearly all of the ARM measurement confidence from that study comes form the calibration of the instruments. However, closing the loop of instrument calibration to a traceable standard sometimes utilizes test equipment. The ARM Program has a number of general test equipment (e.g. digital multimeters, oscilloscopes, signal generators, RF power meters, etc.) that are used for calibrating all instruments, not only at the Southern Great Plains (SGP), but also at other ARM mobile facilities or fixed sites or Mentor institutions. The SGP just completed an activity to identify test equipment used for all ARM instrument calibrations. Specifically, we had to determine: 1) all test equipment that is used, 2) status of certificates of calibrations to NIST standards or a standard calibration procedure for that test equipment, and 3) what additional test equipment needed to be procured. The results are provided in this poster. From this information, we will outline a formal calibration program for test equipment.