Noise eliminating apparatus, weight measurement apparatus, method of eliminating noise, and method of designing digital filter

摘要

A filter coefficient calculator (6) of a weight measurement apparatus calculates filter coefficients using a predetermined arithmetic expression and outputs them to a signal processor (5). The signal processor (5) carries out a filtering process on a weighing signal (D6) using the filter coefficients. The arithmetic expression includes a spectrum parameter specifying a band position of an attenuation band where attenuation must be locally enhanced. A user can input a value of the parameter via a data entry part (7). Each band is specified by the spectrum parameter not as the lowest limit value of a normalized angular frequency, but as the amount of deviation (the amount of displacement) from its center frequency.