| 摘要 |
This instrument contains at least one generator feeding the at least one measurement transducer (1A, ...1N) with voltage of alternating polarity and, connected to the output of the measurement transducer or to the outputs of the measurement transducers (1A, ...1N) at least one amplifier (2A, ...2N) and at least one phase-sensitive rectifier (6). The phase-sensitive rectifier (6) exhibits at least one dual switch (5A, ...5N) connected to the output of the amplifier or connected in parallel to the outputs of the amplifiers (2A, ...2N) and controlled in push-pull with a squarewave signal corresponding to the alternating-polarity voltage, and a first low-pass filter (8) connected to the first switch (51A, ...51N) of the dual switch or of the dual switches (5A, 5N) and a second low-pass filter (9) connected to the second switch (52A, ...52N) of the dual switch or of the dual switches (5A, ...5N). <IMAGE> |
