Megger’s CHM series of cable height meters use ultrasonic sound to determine the height of up to six overhead cables and wires. Designed to address specific measuring requirements on cables up to 75 feet, the CHM600 (C/N 659600) and CHM600E (C/N 659600E) are primarily for power cable applications; the CHM2000 is designed for telecommunication applications. They emit short bursts of sound from the cone- shaped transmitter. The microprocessor calculates the elapsed time for the bursts of sound to be reflected back from the cable. The air temperature is measured by a sensor mounted in front.