To calibrate your light meter, start by inspecting the sensor for dirt or damage, then compare its readings to trusted calibration standards or known light sources like standard lamps or light boxes. Finding ways to optimize the performance of test equipment is one of the primary issues for managers, yet maintaining a large inventory of test and measurement equipment requires a systematic and efficient approach. This makes regular calibration of test and measurement equipment one of the most. “NIST-traceable” metrology labs purchase calibrated transfer standard detectors directly from the National Institute of Standards and Technology in Gaithersburg, MD. Turn on the optical power meter (OPM) using the power button.