How well a load cell performs depends largely on the choice of materials used to make it. Load cell materials include the following parts: strain gauge materials, elastomer materials, patch adhesive materials, sealant materials, lead sealing materials and lead materials.
Strain Gauge and Resistance Element Materials
The strain gauge is the sensing part of the load cell. It converts the size of the external force into an electrical quantity output and is the most important component of the sensor. The commonly used strain gauge base material is a polymer film material, and the strain gauge material is usually high-purity constantan. The performance of a strain gauge is not only related to the base material and constantan purity, but also to the manufacturing process. Improving the level of process technology is also a very important aspect of improving sensor performance.
Elastomeric materials
The function of the load cell elastomer is to transmit external force. It must have the same deformation when subjected to the same force. Because the strain gauge is pasted on the elastomer, the deformation of the elastomer is the deformation of the strain gauge. At the same time, it must also have Resetability, it can automatically reset when the external force disappears. Elastomer materials usually choose various metals, mainly aluminum alloy, stainless steel, alloy steel, etc.
Patch adhesive materials
The patch adhesive firmly fixes the strain gauge and the elastomer together so that their deformations are always consistent. It can be seen that the patch adhesive is also an important component. At the beginning of the 21st century, the most commonly used patch adhesive was the two-component polymer epoxy series adhesive. At the beginning of the 21st century, its performance is closely related to its own purity, mixing method, storage time, curing method, curing time, etc. Please read its detailed introduction carefully before use.
Sealant material
Early load cells were sealed with sealant. Later, due to the development of manufacturing technology, welding technology can improve the stability and service life of the sensor. Although welding technology was widely used in the early 21st century, some important parts still need to be coated with sealant. Sealants generally use silica gel. Silica gel has the advantages of good stability, moisture-proof, anti-corrosion, and very good insulation properties.
Lead seals and lead materials
If the sensor output lead is not fixed, it may be damaged or loose, resulting in unstable signal or no output. At the beginning of the 21st century, sensor outputs were all in the form of connectors, and the material and tightening strength of the connectors would also affect the output. It is best to use connectors with sealants. The internal leads also need to be secured to prevent them from moving around. The quality of the lead is also very important. The order of its material performance from high to low is silver plating, copper wire and aluminum wire. If the surrounding high-frequency signals and radio wave interference are serious, shielded cables must be used: in corrosive environments and flammable and explosive situations, anti-corrosion, flame-retardant and explosion-proof cables must be used, plus casings for protection.
