The working principle and manufacturing process of the strain gauge load cell (hereinafter referred to as the load cell) are determined. It is a resistance strain gauge with four pieces or a multiple of four pieces, which is pasted on the surface of the strain area of the elastic element with strain adhesive. After high temperature curing and post curing treatment, it is firmly integrated into one. Through the assembly and welding of Wheatstone bridge circuits, implementation of various circuit compensation and adjustment, protection and sealing, experimental testing and calibration, all the manufacturing work is completed. From this, it is not difficult to conclude that the deformation of the elastic element of the load cell is transmitted to the sensitive grid of the resistance strain gauge through the adhesive layer of the strain adhesive to complete the conversion task from mechanical quantity to electricity. Therefore, the technical performance and product quality of resistance strain gauges and strain adhesives directly affect the accuracy and stability of the load cell, and are an important part of the quality control of the load cell. This requires that load cell manufacturers should fully understand the design and manufacturing process level of resistance strain gauges in the selection of resistance strain gauges. Focus on the heat treatment and stability treatment process equipment of strain resistance alloy foil; resistance strain gauge substrate and sensitive grid hot pressing process equipment; electronic computer-controlled intelligent etching process equipment; non-prestressed adjustment resistance value and fully sealed grid process equipment ; Graphical recognition of resistance strain gage quality inspection and automatic detection equipment for working characteristics, etc. Specific consideration should also be given to the sensitive grid and substrate materials used in the resistance strain gage; geometry and surface quality; electrical and mechanical properties; sex. Because the excellent base material can maintain the fixed geometry of the sensitive grid, and maintain a high insulation resistance value between it and the elastic element. If the strain adhesive is not properly selected, the thickness of the adhesive film between the resistance strain gauge substrate and the elastic element will be uneven, resulting in an increase in the dispersion of the sensitivity coefficient, and even the nonlinear output of the load cell.

Since the Wheatstone full-bridge circuit is mostly used in the load cell, as long as the temperature of the elastic element is uniform and the resistance strain gauge has consistent thermal output characteristics, the influence of temperature on the resistance strain gauge can be offset, and it is not necessary to use a temperature self-compensating resistor. Strain gages can also meet load cell accuracy requirements. However, from the analysis of the working characteristics of the products of resistance strain gage manufacturers at home and abroad, it is not difficult to conclude that due to the difference in the quality of the strain resistance alloy foil selected by each resistance strain gage manufacturer, the difference in manufacturing process equipment and conditions, the resistance The temperature characteristics of strain gauges are quite different, and their dispersion is also large.

For resistance strain gages attached to elastic elements, the most obvious disturbance is temperature. On the one hand, the change of ambient temperature changes the specific resistance of the sensitive grid material of the resistance strain gauge, which leads to a change in the resistance value; on the other hand, due to the different linear expansion coefficients of the elastic element material and the sensitive grid material, the resistance strain gauge is thermally deformed. , the additional strain produced by the two is the main source of measurement error. This requires load cell manufacturers to choose resistance strain gauges with small thermal output characteristic deviations or resistance strain gauges with temperature self-compensation functions. The above reasons determine that load cell manufacturers, especially those companies that do not have a resistance strain gauge manufacturing department, must scientifically and rationally select resistance strain gauges for various structural elastic elements.