Electrical discharge currents remote measurement - uses luminous discharge tube, fibre optics and photodiode circuit for optical to electrical transformation

摘要

The current measurement system uses a luminous discharge tube (58) and an associated circuit whose characteristics are chosen so that the tube furnishes luminous pulses. The luminous pulses are produced by relaxation from the current to be measured. A light conductor (62) is placed between the tube (58) and a photodiode (65) or similar component in the measuring unit. The circuit in which the current to be measured is produced is an open circuit and is an ionisation current resulting from a point or corona discharge. The current to be measured is applied to a discharge tube (58) which is brought to a condition such that it furnished relaxation pulses. the luminous pulses are transmitted to the measuring unit by light conductors (62). The light pulses are transformed into electrical pulses at the measuring unit. The frequency of the electrical pulses is characteristic of the ionisation current intensity.