“Illegitimi Non Carborundum”
Last Updated: 11/23/2017 08:25


USAF Metrology, Metrologists, and Precision Measurement Equipment Laboratories (PMEL) USAF Metrologists use state-of-the art measurement principals to maintain the accuracy of their PMEL Laboratory Standards traceable to NIST (formerly The National Bureau of Standards) by regular comparisons to NIST primary standards. Their Laboratory Standards are in turn used to transfer accuracy to virtually all customer test/measurement equipment. Standards maintained, but are not limited to; physical/dimensional measurements (pressure, weight, size, temperature), voltage/current, microwave and radio signals, time, frequency, and radiation. The PMEL customer then uses their calibrated and certified test equipment/devices to measure and transfer accuracies to their mission specific equipment and systems. There are PMEL’s located at hundreds of military bases around the world. By maintaining Standards with accuracies traceable to NIST, USAF Metrologists assure the accuracies of virtually all test and measurement equipment used in all Air Force operations.  PMEL’s also repair and maintain customer’s test equipment as required. Equipment brought to a PMEL is calibrated by comparing its performance, the “unknown”, to “known” laboratory standard values. If necessary, the equipment is adjusted/repaired to comply with its specifications as listed in a Technical Order (TO). If needed, charts are prepared showing corrections/errors to measured results for customer use. Equipment passing calibrations/adjustments will receive the Metrology Technician’s seal of approval in the form of an imprint
of their personal “K-Stamp” on the Status form attached to the equipment. When unable to adjust equipment measurement results to meet specifications, the equipment is returned to the customer with a red tag indicating the equipment could not be restored to its stated specifications and is no longer usable. PMEL’s were once staffed by select enlisted USAF personnel who passed the rigorous PMEL entrance exam by achieving a raw score of 90 or better. These selected individuals would then attend Metrology Training located at Lowry AFB, CO. Course length varied over the years from its original 18 weeks to 46 weeks in 1968, returning to 32 weeks in 1972. The original PMEL students had to have attained the rank of at least E3 and have at least three years left on their current enlistment. In this way, a PMEL lab would consist of individuals possessing not only common Metrology skills, but also skills from their originating career fields thus enabling PMEL’s to provide maintenance assistance to any USAF maintenance activity. While other branches of service defined and implemented their own requirements for maintenance and calibration services, the focus of this website is from an Air Force perspective. The USAF’s active involvement and close association with NIST, working through the Aerospace Guidance and Metrology Center (AGMC) in Ohio, has been instrumental in the evolution of the art and ( Continued )