Currently, most customers either send or hand carry artifacts to NIST for calibration. Customers then use the calibrated artifacts to calibrate meters that in turn calibrate multifunction calibrators used to calibrate working test equipment. Nile Oldham works with customers performing remote voltage calibrations over the Internet. 3 NIST metrologists calibrate the precision DMM using a reference multifunction calibrator that NIST has calibrated using its own artifact standards. The standards are those that NIST maintains, such as the primary bank of voltage, resistance, and capacitance standards that I previously described.
Customers use the DMM to calibrate their multifunction calibrators.
A precision DMM sits on the shelf above the calibrator. When a customer using this service calibrates its own multifunction calibrator with the precision DMM, NIST metrologists use an Internet camera to observe the client's procedures. NIST metrologists can guide customer metrologists through the calibration process. Previously, NIST metrologists had to rely on fax, e-mail, and the phone to conduct these calibrations. Live audio and video over the Internet reduce hookup connection errors and minimizes incorrect test procedures.