NOISE ELIMINATOR FOR GRAVIMETRY AND NOISE ELIMINATION METHOD FOR GRAVIMETRY

Japanese Patent JP3771195

B2

PROBLEM TO BE SOLVED: To damp a constant-period oscillating noise whose frequency changes with high precision, by causing filter characteristics to follow and change with respect to the frequency variation of the constant-period oscillating noise.
SOLUTION: A noise eliminator 1 is provided with an amplifier 10 which amplifies a measured signal ms outputted from a weighting apparatus 3, an analog filter 11, an ADC 12, a digital filter 14, a coefficient control unit 13, and a data input unit 15. The digital filter 14 is a notch filter which damps the frequency components of a weighed signal D(n) outputted from the ADC 12 by a plurality of notches (blocking regions). The transfer function of this digital filter 14 is represented by the product of a plurality of factors having roots which correspond to the notches. The control unit 13 changes the frequency component of a root corresponding to a notch designated from among the notches, develops the transfer function of the re-formed digital filter 14 into a polynomial after that, and computes a new series of filter coefficients on the basis of the polynomial.

Takashi Kimura
Nakajima Masaki
Shuji Murata
Yukio Wakasa
Kazuhiro Suhara

JP2002143110A

April 26, 2006

May 17, 2002

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ISHIDA CO.,LTD.

G01G23/37; G01G3/147; G01G23/10; H03H17/02; (IPC1-7): G01G23/37; H03H17/02

JP3170031A
JP9210758A
JP7134058A
JP6350403A

Shigeaki Yoshida
Yoshitake Hidetoshi
Takahiro Arita

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