digital filter for digital scale, including digital scale digital scale digital filter and method of filtering process waves

A digital filter for a digital scale (1), comprising: a filter FIR 5 (31) to perform a filtering process wave with respect to a digital weighing signal containing an oscillation component; a determination device (32), wherein the determination device is configured to determine if an amplitude of an oscillation component contained in a signal digital weighing derived by performing the filtering process by waves by the FIR filter comes within a range allowable predetermined damping, at every predetermined digital signal weighing within a sampling weighing cycle; and a control device (33); characterized in that the FIR filter includes a fixing section (311) to remove a component of swing in a predetermined frequency range and a matching section (312) to remove a component in a range of oscillation frequency changing; the control device is configured to change the frequency range of the oscillation component to be removed by the matching section (312) by changing a filter coefficient of the matching section based on a result of determination by the device determination; and the control device (33) is configured to change the filter coefficient adaptation section (312) based on the digital signal weighing cycle previous weighing.