Method of processing the output signal of a measuring transducer and force measuring device for carrying out the method.

Abstract

A method serves to process output signal of a measuring transducer in a force-measuring device, in particular in a balance, wherein the measuring transducer produces a measuring signal representative of a load acting on the device and the measuring signal is filtered in a variable analog filter and / or, after processing in an analog / digital converter, the measuring signal is filtered in a variable digital filter, in order to remove unwanted signal components that are caused by disturbances affecting the force-measuring device, in particular by changes in the weighing load. The measuring signal is monitored in regard to the occurrence of a change in the weighing load and after a load change has been detected, at least one filter parameter of the filter is reset and then varied as a function of time in accordance with a prescribed time profile fc(t), so that the filter is opened after a load change has been detected and then closed again to the point where a predefined filter characteristic has been attained which is determined by the end value of the at least one filter parameter. By using this method, it is possible with simple measures to realize noticeably shortened transient settling times of the force-measuring device after a load change has occurred.

Description

technical field [0001] The invention relates to a method for processing the output signals of a measuring sensor and a force measuring device, in particular a balance, which operates according to the method and is equipped with a measuring sensor and whose output signals are processed according to the method. Background technique [0002] Force measuring devices, such as scales based on the principle of electromagnetic force compensation or strain gauge technology (see reference [1], Mettler Toledo GmbH's company publication "Bauen Sie Ihre", January 2001 auf solidem Grund! (Building your own quality on a solid basis)" on pages 14 to 15), the measurement accuracy of the measurement depends on many influencing factors, which are described in reference [2], published in April 2001 by MettlerToledo GmbH " (Introduction to Weighing)". Particularly undesirable are disturbances caused by mechanical factors such as vibrations or shocks, which means that scales using analog sign...

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Problems solved by technology

[0010] However, with existing solutions, oscillations with rapidly changing amplitudes that occur with changes in the weighing load are only corrected to a small extent, and if at the same time it is necessary to achieve a very short settling time of the instantaneous oscillation after the change in the weighing load , some of which will be very complex and expensive

Because in the schemes adopted before, in most cases the aim is to achieve a compromise between the strongest damping and the longest response time of oscillatory disturbances on the one hand, and the lowest possible response time of oscillatory disturbances on the other hand. Weak damping and shortest response time, none of the solutions so far has achieved good enough results in terms of response time and signal interference filtering for the most stringent requirements

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