The performance of the weighing sensor depends on the material

The performance of weighing sensors largely depends on the selection of manufacturing materials. The material of the weighing sensor includes the following parts: strain gauge material, elastomer material, patch adhesive material, sealant material, lead sealing material, and lead material.

Load Cell Material

1. Strain gauge and resistance element materials

The strain gauge is the sensing part of a weighing sensor, which converts the magnitude of external force into electrical output. It is the most important component of the sensor. The commonly used strain gauge substrate is made of polymer thin film material, and the strain material is usually high-purity constantan. The performance of strain gauges is not only related to the purity of the substrate and constantan, but also to the manufacturing process. Improving the level of process technology is also an important aspect of improving sensor performance.

2. Elastomer material

The function of the elastic body of the weighing sensor is to transmit external forces, and it must have the same deformation when subjected to the same force, because the strain gauge is attached to the elastic body, and the deformation of the elastic body is the deformation of the strain gauge; At the same time, it must also have resetting ability, which can automatically reset when external forces disappear. Elastomer materials are usually selected from various metals, mainly aluminum alloy, stainless steel, and alloy steel, etc.

3. Chip adhesive material

Patch adhesive is used to firmly fix strain gauges and elastomers together, ensuring that their deformation is always consistent. It can be seen that the patch adhesive is also an important component. Currently, the patch adhesive used is a two component polymer epoxy series adhesive. Its performance is closely related to its purity, mixing method, storage time, curing method, curing time, etc. Before use, it is important to carefully read its detailed introduction.

4. Sealant material

Early weighing sensors were sealed with sealant, but later due to the development of manufacturing technology, welding technology can greatly improve the stability and service life of sensors. Although many welding techniques are now used, some important parts still need to be coated with sealant. Sealants generally use silicone, which has the advantages of good stability, moisture-proof, anti-corrosion, and excellent insulation performance.

5. Lead Sealing and Lead Materials

If the output lead of the sensor is not fixed, it may be damaged or loose, resulting in unstable signals or no output. Nowadays, sensor outputs use connectors, and the material and tightening force of the connectors can also affect the output. It is best to use connectors in conjunction with sealant. Internal leads also need to be fixed to prevent them from moving around. The quality of the lead wire is also important, and its material properties are arranged in descending order from silver plated, copper wire, and aluminum wire. If there is severe interference from high-frequency signals and radio waves around, shielded cables should also be used; In corrosive environments and flammable and explosive environments, it is necessary to use anti-corrosion, flame-retardant, and explosion-proof cables with additional sleeves for protection.