The load cell can be said to be a key component in the measurement of a weighing instrument, as a metaphor for the “heart” of a person. The performance of the load cell plays a vital role in the accuracy and stability of the electronic weighing instrument. What factors and parameters should be considered in the selection of load cells are the primary thresholds that trouble the selection personnel.
One classification of load cell:
According to the working principle of the load cell, it can be divided into the following methods: (1) Resistance strain type. Differential transformer type. Capacitive type. Piezomagnetic type. Piezoelectric type. Vibrating wire type. (2) According to the force, it can be divided into normal stress type and shear stress type. (3) According to its structure, it can be divided into S type load cell. Single point sensor, cantilever beam sensor. Bridge type load cell. Disc type Load cell. Column type load cell. Pressure load cell manufacturer. Spoke type load cell, etc. (4) Depending on the material of the load cell, there are titanium diamond type and aluminum alloy type and so on.
2.Influence of environmental factors:
First of all, consider the actual working environment in which the load cell is used, including high temperature, humidity, high corrosion, the influence of electromagnetic fields on signal output, and flammable and explosive environments.
1 High temperature: High temperature will cause the weighing sensor to open up the solder joints, melt the glue, and change the internal stress of the elastomer. High temperature load cells should be used for personnel used in high temperature environments. There must be technical measures such as temperature compensation.
2 Humidity: Humidity will cause short circuit effects on the load cell, so in this environment, a load cell with high airtightness should be selected. Different weighing sensors use different secret methods, and there will be great differences. For those who use it in this environment, they must be more discerning about the seal.
3 Highly corrosive environments: Highly corrosive environments, including moisture and acid, will cause damage or short-circuit effects to the elastomer of the load cell. For elastomers used under severe corrosion, the surface must first be sandblasted or treated with surface technology to play a role in corrosion resistance.
4 The output signal of the electromagnetic field: the electromagnetic field has an interference effect on the output signal of the load cell, so the shielding performance of the load cell should be strictly checked to see if it has a good ability to resist electromagnetic radiation.
5 Inflammable and explosive: Inflammable and explosive not only can cause thorough damage to the load cell, but it is also very likely to cause personal safety threats to the staff if the operation is improper. Therefore, the load cell used in this environment must be selected Explosion-proof load cell. The sealed outer cover of this load cell should not only consider its tightness, but also consider the degree of explosion-proof level.
Three selection of weighing sensor range:
The range of the load cell is selected according to the maximum weighing value of the weighing platform. The number of sensors used on the load cell table, the self-weight of the weighing body, the possible partial load and other factors are comprehensively evaluated to determine the final weighing cell Use range. The closer the load cell range is, the higher the accuracy of the scale body’s own weight. Therefore, when selecting the load cell range, it is necessary to consider the weighing body weight, tare weight, partial load, vibration impact, load and other factors to ensure the service life of the load cell.
Fourth, the selection of the accuracy level of the load cell:
The accuracy grades of load cells include rated load, sensitivity, nonlinearity, hysteresis error, repeatability error, creep, zero point output, input, output, insulation resistance, temperature compensation, elastomer material, and more technical index requirements. While selecting the load cell, accuracy and accuracy are a necessary condition for the load cell.
Five Conclusion
Based on the above factors and the parameters that need to be referred to are the basic theoretical knowledge for the selection of load cells, but what kind of load cell combined with its own conditions can achieve low cost, and the use of high efficiency requires professional theory and practice. Circumstances are combined.
