Cable Height Meters
The cable height meter (CHM) is an ultrasonic device to check wire clearance to ground and spacing of overhead conductors. It can also measure the distance to other hard surfaces.
- safe - no contact with conductors/wire
- simple - one button-one man operation
- easy to use - stand underneath, press the button and read the measurement
- fast - measures in seconds
- accurate - less than 0.5% error in reading.
From the cone of the instrument, the transducer sends out a burst of sound
- The sound 'bounces' off the cable and needs to be received in the cone, as the transducer is at the same time the transmitter and receiver
- The CHM clocks the amount of time taken
- Distance is calculated based on speed of sound; adjusts for air temperature
- The microcontroller calculates the distance in either imperial or metric.