CPC G01M 5/0008 (2013.01) [G01V 1/18 (2013.01); H03H 7/06 (2013.01)] | 8 Claims |
1. A measuring system for measuring a displacement of at least one point of a bridge, the bridge having a resonance frequency comprised in a frequency band [fl, fh] where fl<fh, comprising:
a geophone configured to be applied in the at least one point of the bridge, the geophone having a resonance frequency fr greater than fh and a frequency response for f<fh substantially equal to a frequency response of a double shunt;
an analog compensation device connected in series to the geophone and having a frequency response equal to a frequency response of a double integrator in the frequency band [fl, fh], so that a series connection of the geophone and the analog compensation device has a frequency response with a substantially constant module in the frequency band [fl, fh];
an analog integrator device connected in series to the analog compensation device; and
an analog/digital converter device connected in series to the analog integrator device, the analog/digital converter device being configured to convert an output signal from the analog integrator device into a digital signal,
wherein the analog compensation device comprises:
a first amplification stage; and
a double low-pass filter connected in series to the first amplification stage and having a cutoff frequency ft no greater than fl, the double low-pass filter being an active filter that comprises a second amplification stage.
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