Megger Chm Series Cable Height Meter

The CHM Series of Cable Height Meters utilizes ultrasonic sound to determine the height of up to six overhead cables and wires. The instruments are designed to address specific measuring requirements on cables up to 75 feet (23 m). The CHM600 (C/N 659600) and CHM600E (C/N 659600E) are designed primarily for power cable applications, while the CHM2000 is designed for telecommunication applications.

These meters work by emitting short bursts of ultrasonic sound from a cone-shaped transmitter. As these sound waves travel upwards, they reflect off the overhead cables and return to the device. The built-in microprocessor calculates the time taken for these sound waves to travel back and forth, allowing it to determine the height of the cables.

The precision of the CHM Series meters is further enhanced by an integrated temperature sensor located at the front of the instruments. This sensor detects the ambient air temperature, which is crucial because the speed of sound varies with temperature changes—approximately 0.2 percent per degree Celsius. The sensed temperature is factored into the calculations by the microprocessor to ensure the accuracy of the height measurements.

The results from the CHM Series can be displayed in either feet and inches or meters, according to the user’s preference, making the instruments versatile across different regions and standards. This feature is particularly useful in settings where precise and reliable measurements are necessary, such as during the installation, maintenance, or inspection of overhead cables.

Designed to measure up to six cables and capable of reaching heights up to 75 feet (approximately 23 meters), the CHM Series meters are essential tools for professionals working in the power and telecommunications sectors. These meters not only provide rapid and accurate measurements but also enhance safety by eliminating the need for physical measuring methods, which can be risky and impractical with high overhead cables.