General Radio 1482M

The 1482M Standard Inductor is an accurate, highly stable standard of self inductance for use as a low-frequency reference or working standard in the laboratory. Records extending over 13 years, including those of inductors that traveled to national laboratories in several countries for calibration, show long-term stabilities well within ?0.01%. It is a uniformly wound toroid on a ceramic core. It has a negligible external magnetic field and hence essentially no pickup from external fields. Nominal Inductance: 200 mH Adjustment Accuracy: ?0.1% Resonant Frequency: 39.0kHz