Overhead Line Corrosion Detector

An example of high speed full duplex radio comms.

Cormon Ltd. of Lancing, Sussex, is producing a system, developed by the CEGB to detect corrosion in overhead electricity power lines, under license. The corrosion detector and a data telemetry system are carried in a lightweight trolley, which is towed along the conductor by a second lightweight motorised radio-controlled trolley. The data telemetry and radio control systems are both designed and produced by Magenta Products Ltd. The radio telemetry control system for the motorised trolley uses a high security VHF up-link from a hand-held transmitter to control the speed and direction of travel of the trolley along the over-head line. For safety reasons, the system incorporates a number of interlocks to prevent dangerous operation of the trolley. All transmissions are checked for corruption by address and Cyclic Redundancy Code information. Data from the corrosion detector and a distance encoder on the passive trolley is transmitted by the UHF down-link to a receiver on the ground for subsequent display and recording. Compressed band-width modulation techniques are used to achieve the necessary data-throughput of 4800 bit/s using a standard 25 kHz radio channel.

This system was implemented with earlier derivations of the MP1809 and MP2501 radio data modules.