Calibration Procedures for Inductance Standards Using a Commercial Impedance Meter as a Comparator

摘要

Procedures for calibrating customers' inductance standards using a commercial impedance meter to compare them with NIST inductance standards by a substitution method are reported. These procedures are based on a six-month evaluation of the meter by measuring a group of six NIST inductance standards of different values at a frequency of 1 kHz. For each inductance standard, the results of measurements with the meter and the Maxwell-Wien bridge, which is used to realize the henry at NIST, are analyzed to determine the stabilities of the standards and the impedance meter as well as to estimate the random transfer uncertainty of the meter measurements. Values of inductance obtained using the Maxwell-Wien bridge are compared with corresponding values of inductance obtained with the meter by substituting customers' inductance standards with the six NIST standards over a period of six months. The statistical analyses used to assure that measurements made using such procedures are in control are described, as well as future plans to expand the substitution technique to include other values of inductance standards at various frequencies.