摘要 |
A measuring circuit comprising a symmetric transmission line connecting a transducer to a measurement amplifier and to a fault indicating signal amplifier, the transducer delivering symmetric input signals to said amplifiers, the first amplifier delivering a measuring signal representing the difference of its input signals and the fault indicating signal amplifier delivering a fault indicating signal representing the sum of the input signals. An auxiliary signal injected to the terminals of the transducer the invention enables the measuring circuit to evaluate the quality of the measuring circuit during operation of the tested machine and also when the machine is at rest .
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