AN ELECTROMAGNETIC ENVIRONMENTAL MONITORING-SYSTEM THAT INTERLOCKS WITH MALFUNCTIONS

Since most electromagnetic malfunctions are of high speed and of a pas sing nature, it is difficult to specify the cause, The objective of th is paper is to propose a monitoring system which can detect the electr omagnetic waves in the time domain when malfunctions of electrical equ ipment occurs. The peak value of the detected waveform, the duration o f the waveform, and the energy in an arbitrary frequency region were u sed as procedures to evaluate the measurement data. In this system, by integrating,the energy is defined as the energy spectrum of the detec ted waveform over arbitrary frequency regions. The monitoring system f abricated for trial was investigated in terms of the processing time s uch as the data transfer time. It was confirmed that almost I s is nee ded for storing the measured data and that this time duration is the m aximum delay in the control of the present system. Using the transmiss ion module as the equipment under test, we performed an experiment to apply the lightning surge on a building which simulates a telephone ex change office to verify the effectiveness of the monitoring system, Th e measurement results indicate that the amplitude and the energy of th e current waveform flowing into the equipment from the grounding wire become several ten times those from other lines. As a result, the dete cted waveform, raised the possibility of significant cause of trouble to the equipment.