The acoustic device for controlling a distance which is testable through variation of the supply voltage.

摘要

The control by the acoustic emission of industrial installations that are inaccessible in operation need a means of a test for the good operation of the various lines of measurements 1. / p & & p & according to the invention, each of those - ci, which comprises at least one sensor 2, a preamp 3 and a connecting line 5 is a processing unit 4 of the acoustic signal, is mounted in the test position or in the position measurement by variation of the dc supply. In a first variant, the voltage drop, which is insensitive to the preamplifier 3, sets off a relay 16, which places a list of the pulses of the test 15 is connected between the sensor 2 and the preamplifier 3, at a distance from the processing unit 4. In a second variant, more simply, the cut-off of the power supply 8 sets off the relay 15 which is placed outside the circuit the preamplifier 3 and a list of pulses of test 15 located on the processing unit 4. / p & & p & the present invention makes it possible to test a distance of the measurement lines without lines of the monitoring or operators.