Device for measuring the level of a variable signal with logarithmic conversion
AssigneeSafare-Crouzet
InventorsBernard J. Saint-Oyant, Jean G. Roche
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Abstract
A device for measuring the level of a variable signal delivered by a sensor. It comprises a series of attenuators, receiving the signal from the sensor, a squaring and integrating chain for converting the value of the signal delivered by the attenuators into its root-mean-square value, and a recorder. The attenuations are calibrated in dB. The device comprises an AGC circuit, receiving the output signal from the squaring and integrating chain, for switching the attenuators and controlling the recorder. The output signal from the attenuators is maintained constant.
Claims8
In a device for measuring, with logarithmic conversion, the level of a variable signal delivered by a sensor, comprising an amplification chain made up of a series of attenuators receiving the signal delivered by the sensor, a squaring and integrating chain for effecting the conversion of the value of the signal delivered by the amplification chain into its mean-square value, and a recorder for recording the level of the signal to be measured, characterized in that said attenuators are calibrated in dB and the device further comprises an automatic gain control circuit for receiving the output signal from the squaring and integrating chain and generating a digital control signal used to switch said attenuators in order to maintain constant the mean-square value of the output signal from said amplification chain and consequently the output signal of said squaring and integrating chain and a digital to analog converter for receiving an output signal from the automatic gain control circuit and generating an analog signal, said recorder recording said analog signal.
Dependencies are inferred from the claim text.