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Measuring excellence by the milligram

  • Published
  • By 2nd Lt. Allison Egan
  • Joint Base Charleston Public Affairs
When not supporting the U.S. Coast Guard, Navy and the Air National Guard, the Precision Measurement Equipment Laboratory uses its technical capabilities at Joint Base Charleston Air Base to support a range of technologies including aircraft countermeasures test sets and night vision goggle testers. 

“One of the difficulties is explaining something you can’t see," said Staff Sgt. Cassandra Lopez. "In this field of work, accuracy demands patience.” 

Separated into two divisions, PMEL consists of an electronics and a physical dimensional section. In electronics, technicians monitor power, frequency, voltage, current and resistance. In this section, equipment such as digital multimeters and signal generators, are calibrated.

In the physical dimensional section, technicians verify equipment dealing with, but not limited to, pressure, temperature, humidity and force. Some examples are, pressure gauges and thermometers. 

Specifically, the tests require extremely precise and reliable measurements. Due to the sensitivity of the equipment, the slightest deviation in temperature can affect the laboratory. If the temperature exceeds the six-degree window of functionality, operations must be stopped. 

In optimal working conditions, technicians using the appropriate equipment can measure the smallest fluctuation in weight. When using an Analytical Balance, Senior Airman Jack Steinberg, a 437th Maintenance Squadron test measurement diagnostics equipment technician, is able to measure the weight of a penned signature, weighing 0.5 milligrams.  

Along with a keen eye for details, the PMEL profession requires patience. When verifying test points on a particular item, it can take up to an hour for just one test point to stabilize, to obtain an accurate reading. 

The proper preparation, Steinberg emphasizes, is required to ensure accuracy.

 “Without that attention to detail, you can run into traceability problems," he said. "You must stay precise and consistent.” 

Though maintenance is most commonly associated with the flightline, PMEL provides services that also extend beyond the Air Force mission. With technology spanning all branches of the military, PMEL is constantly calibrating, troubleshooting and repairing various forms of equipment.  

“There is always something to do,” Lopez said. “There’s always something to fix.”