The DC5010 Frequency Counter Plug-In makes frequency measurements to 350 MHz. Measurement functions include: Reciprocal Frequency Measurement, Period, Width, Time from A to B, Events B during A, Totalize A, A+B, A-B, Ratio, Rise/Fall, Time Manual, Arming, Null. Measures DC and True RMS ACV, Ohms, and provides a diode test function. Internal math capabilities include averaging, nulling, offset, scaling, dB, and HI/LO/Pass sorting. 9 digit display. Used in Tek TM 5000-Series mainframes.