Abstract:
A method serves to correct drift phenomena, in particular creep effects, occurring in an electronic balance that has a measuring transducer through which a measuring signal is formed which is representative of a load applied to the force-measuring device. The measuring signal is delivered by way of an analog/digital converter to a signal-processing unit that is supported by at least one processor, said signal-processing unit being capable of compensating drift deviations, for which purpose the signal-processing unit, via the processor, accesses drift parameters that are stored in a memory unit and serve as basis for calculating a time-dependent correction value by which the drift error of the measuring signal (ms) is corrected. At time intervals that are either controlled automatically or chosen by the user, new optimized values for the drift parameters are determined automatically by the processor and the signal-processing unit under the control of an optimization program that is stored in the memory unit, and the new optimized values are filed in the memory unit.
Abstract:
A method serves to optimize the behavior of an electronic force-measuring device, in particular a balance that comprises a measuring transducer through which a measuring signal is formed which is representative of a load applied to the force-measuring device, which measuring signal is delivered to a signal-processing unit that is supported by at least one processor and at least one memory storage unit and serves to process digital signals. First characteristic traits for the condition of the force-measuring device are determined, the first characteristic traits being the result of internal and/or external factors affecting the force-measuring device, and/or second characteristic traits for the force-measuring device are determined from the analysis of at least one signal profile of the measuring signal, whereupon the condition of the force-measuring device is determined on the basis of the first and/or second characteristic traits, and the further processing of the measuring signal and/or the operation of the force-measuring device is controlled accordingly. Based on the condition of the force-measuring device that was determined, the processing or evaluation of the signal as well as the use of optimizing measures that serve to determine, e.g., optimized correction parameters such as drift parameters or filter parameters can be advantageously controlled.
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.
Abstract:
A force-measuring apparatus, particularly a weighing cell, has a stationary part 10, a load receiver 60, a measuring transducer 138, and a lever 100 for transmitting a force from the load receiver to the measuring transducer. An improved arrangement is proposed for changing the lever ratio by providing at least two different locations so that the fulcrum pivot flexures can be attached either at positions 112/212 and 118/318 or, alternatively, at positions 114/214 and 116/316 of the lever/stationary part.