The Model JM861 is a high-performance AC/DC clamp meter designed for use with oscilloscopes, waveform analyzers, and other measurement instruments that benefit from accurate frequency response. It features a specialized circuit with three selectable ranges to optimize frequency response and accurately measure AC current waveforms. The device provides a proportional millivolt output for direct reading on oscilloscopes, with a large jaw opening suitable for testing on cables and bus bars. It supports a nominal range of up to 3000A AC, with a transformation ratio of 3000:3 and an output of 1mA/A. Designed for compatibility with digital multimeters, power meters, harmonic analyzers, recorders, and other AC current measurement devices, it is ideal for electrical utility, HVAC/R, industrial maintenance, laboratory testing, plant maintenance, and power quality applications.