chm-series-ds
CHM Series
Cable Height Meters
The CHM Series of Cable Height Meters utilize ultrasonic techniques 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.
The Cable Height Meters emit short bursts of sound which originate from the cone shaped transmitter. The microprocessor in the instruments calculates the elapsed
time for the bursts of sound to be reflected from the cable back to the instruments. The result can be displayed in either feet and inches or meters. However, before the final measurement can be displayed, the air temperature must be measured because the speed of sound varies at approximately 0.2 percent per degree Celsius.
A temperature sensor, mounted at the front of the instruments, senses the actual air temperature. This information is sent to the microprocessor and incorporated
into the algorithm. The distance is then displayed in meters or feet and inches depending on which was selected.
APPLICATIONS
The Cable Height Meters are capable of measuring the lowest cable, provided it is within range. Additionally the spacing between the next five cables can be displayed. This
is accomplished by standing directly beneath the cable and aligning yourself longitudinally (looking down the line). Simply press the “ON” button to power the instrument up and allow the temperature to stabilize. Press the ‘MEASURE’ button and if necessary gently “rock and tilt” the instrument until a stable reading is obtained. Applications include
measuring cable heights of:
- Telephone lines
- Distribution lines
- Transmission lines
- Cable television (installers and contractors)
- Street lights
- Sag (lowest point to ground)
- Separation between up to six cables
The instrument can be used to ensure that OSHA overhead clearance regulations are met at construction sites. It also provides a safer way to measure cable heights on highly
congested roadways.
Additionally the Cable Height Meters offer an easy way to check whether the device has remained in calibration since its purchase date. Switching to ‘CAL’ mode also allows the instruments to be used indoors.
FEATURES AND BENEFITS
Ease-of-use — Simple, three button operation ensures fast, effective measurements with a minimum of operator training.
Compact size — Its light weight and hand-held portability allows easy transport and multiple measurements.
Inherently safe — No physical connection to cables or wires required to obtain measurement.
