News - Ningbo Santwell Imp & Exp Co.,Ltd

Load cell classification The classification of load cell is based on its output signal. The load cell can be divided into: Analog sensor-convert the measured non-electrical quantity into an analog electric signal. Switch sensor-when a measured signal reaches a certain threshold, the sensor correspondingly outputs a set low or high level signal. Digital sensor-convert the measured non-electrical quantity into a digital output signal (including direct and indirect conversion). Classification of load cells According to the working principle of load cells, they can be divided into two categories: physical sensors and chemical sensors: Classification of the working principle of load cells. Physical sensors apply physical effects, such as piezoelectric effect, magnetostriction, ionization, polarization, pyroelectric, photoelectric, magnetoelectric and other effects. Small changes in the measured signal volume will be converted into electrical signals. Chemical sensors include those that take chemical adsorption, electrochemical reactions and other phenomena as causal relationships. Small changes in the measured signal will also be converted into electrical signals. Some sensors can neither be classified into physical or chemical categories. Most sensors operate on the basis of physical principles. There are many technical problems with chemical sensors, such as reliability issues, the possibility of mass production, price issues, etc. If such problems are solved, the application of chemical sensors will have a huge growth. Classification of load cells According to their use, sensors can be classified as: pressure sensitive and force sensitive sensors, position sensors, liquid level sensors, energy sensors, speed sensors, thermal sensors, acceleration sensors, radiation sensors, vibration sensors, humidity sensors , Magnetic sensor, gas sensor, vacuum sensor, biological sensor, etc. According to the conversion method, the load cell is classified into 8 types: photoelectric, hydraulic, electromagnetic, capacitive, magnetic pole change, vibration, gyroscope, and electric cathodic strain. The resistance strain is the most widely used. Principle of Resistance Strain Type Load Cell The resistance strain type load cell is based on the principle: the elastic body (elastic element, sensitive beam) produces elastic deformation under the action of external force, so that the resistance strain gauge (conversion element) pasted on its surface also deforms, the resistance strain gauge [1] After deformation, its resistance value will change (increase or decrease), and then the resistance change will be converted into an electrical signal (voltage or current) by the corresponding measuring circuit, thus completing the transformation of external force into electricity. Signal process. Resistance strain gauge The resistance strain gauge is to mechanically distribute a resistance wire on a substrate made of organic material, which becomes a strain gauge. One of his important parameters is the sensitivity coefficient K. Elastomer The elastomer is a structural member with a special shape. It has two functions. The first is that it bears the external force received by the load cell, and the external force produces a reaction force to achieve a relative static balance; second, it has to generate a high-quality strain field (zone) so that it can be pasted in this area. The resistance strain gauge is ideal to complete the conversion task of strain jujube electrical signals. Detection circuit The function of the detection circuit is to convert the resistance change of the resistance strain gauge into a voltage output. Because the electric bridge has many advantages, such as the ability to suppress the influence of temperature changes, the lateral force interference, and the more convenient solution to the compensation problem of the load cell, the electric bridge has been widely used in the load cell.