The Greenlee CDM-75 (52087343) Cable Distance Meter, 75 ft., is a handheld meter for measurement of cable sag, cable height distance and overhead clearance of conductors. Itis a modern alternative to telescopic measuring poles. The Cable Distance Meter utilizes ultrasonic signals to determine the height of overhead cables up to 75 feet (23m). Used by line operators within the utility industries such as electricity and telecommunications, the Cable Distance Meter measures up to 6 wires.

The Cable Distance Meter is capable of measuring up to six cables (provided they are within range). This is accomplished by standing directly beneath the cable and aligning longitudinally (looking down the line). Simply press the "ON" button to power up the instrument and allow the temperature to stabilize. Press and hold the "MEASURE" button and, if necessary, gently rock and tilt the instrument until a stable reading is obtained.

The Cable Distance Meter emits short bursts of sound which originate from the cone-shaped transmitter. The microprocessor in the instrument calculates the elapsed time for the bursts of sound to be reflected from the cable back to the instrument. The result can be displayed in either feet and inches (imperial) or meters (metric) format. To account for the fact that speed of sound varies with temperature, a temperature sensor mounted at the front of the instrument senses the actual air temperature and automatically compensates.