6625-00-643-3210 (LM15)
NSN 6625-00-643-3210 (NIIN 00-643-3210) is an electrical frequency meter in Federal Supply Class 6625, Electrical And Electronic Properties Measuring And Testing Instruments — an instrument which measures the rate of regularly recurring variations in an electric current or voltage and is usually calibrated in hertz (cycles per second. Manufacturer part number LM15 (Naval Ship Systems Command, CAGE 80064).
Key specs: internal frequency calibrating crystal; AC or DC circuit current for which designed; 50 to 60 hertz frequency; full characteristics table below. NIIN assigned January 1963; export Schedule B 9030.90.8030.