Strain gauge force and load cells are widely used in industries such as manufacturing, national defense, and transportation. They are mainly used as core components of various electronic weighing instruments and production process control equipment. Their performance directly affects the accuracy of force measurement or control. Nonlinear error is the most important technical indicator of strain gauge force and load cells, and it is also an important performance indicator of high-precision force and load cells. High-precision force and load cells are mainly used for the calibration of force standard machines and as core components of high-precision electronic weighing instruments
Other occasions where the linear error measurement is required to be relatively high. Some sensors have relatively large nonlinear errors due to their own structural limitations. Meanwhile, some sensors may encounter various errors throughout the production process, failing to meet the design requirements. As a result, the nonlinear errors of the sensors do not meet the design and customer usage requirements. Especially for large-range force and weighing
The sensor is large in size, and the processing and surface mount procedures are both time-consuming and labor-intensive. It is a strain sensor with a torsion ring structure. "Passing on
The repeatability error and zero return characteristics of the sensor are all good. However, when the nonlinear error exceeds the tolerance, the linear compensation method can be implemented through semiconductor strain gauges and nickel foil strain gauges for adjustment.
Testing and analysis of sensors before nonlinear compensation
The LRT-50 strain gauge force and load cell shared in this article, during the testing process, two of the sensors could meet the requirements in terms of zero return and repeatability, but their nonlinear errors exceeded the requirements. The specific test data are shown in Tables 1 and 2. The nonlinear error curves of the two sensors (see Figure 2) are analyzed as a decreasing parabola, similar to the nonlinear error of a cylindrical sensor. That is to say, as the load increases, the output will show a decreasing trend.
Through the analysis of the above data, the nonlinear error of the sensor after compensation has been reduced from 0.1%FS to approximately 0.03%FS, showing a very significant improvement. However, for nonlinear correction of different sensors, a large number of experiments are still needed to fix the parameters of the compensation resistor to facilitate mass production in the later stage.