The load cell is actually a device that converts the quality signal into a measurable electrical signal output. The sensor should first consider the actual working environment of the sensor, which is essential for the proper selection of the load cell, it relates to the sensor can work properly and its safety and service life, and even the entire instrument reliability and safety Sex. In the load cell main technical indicators of the basic concepts and evaluation methods, the old and new GB quality differences. There are several types of S-type, cantilever type, spoke type, plate ring type, membrane box type, bridge type, cylinder type and so on.
1, sensitive components
Directly perceive the measured (mass) and output other elements that have a certain relationship with the measured relationship. Such as the resistance strain gauge load cell elastomer, is the quality of the measured object into a deformation; capacitive load cell elastomer will be measured to the quality of displacement.
2, transform components
Also known as sensor components, is the output of sensitive components into a signal to facilitate the measurement. Such as a resistance strain gauge strain gauge strain gauge (or resistance strain gauge), the deformation of the elastic body is converted to changes in the amount of resistance; capacitive load cell capacitor, the elastic body of the displacement into the capacitance changes The Sometimes some elements have both the function of both the sensitive element and the transform element. Such as voltage-type load cell piezoelectric material, under the action of external load, in the deformation of the output power at the same time.
3, measuring components
Transform the output of the transform element into an electrical signal to facilitate further transmission, processing, display, recording or control. Such as resistance strain gauge load cell in the bridge circuit, piezoelectric load cell charge preamplifier.
4, auxiliary power supply
Provides energy for the sensor's electrical signal output. General load cell need to be outside the chain power to work. Therefore, as a product must be marked with the power supply requirements, but not as part of the load cell. Some sensors, such as magnetic speed sensor, because of his output of the larger energy, so do not need auxiliary power can work properly. So not all sensors have auxiliary power.
Variation refers to the weighing instrument measured variables (which can be understood as the input signal) from the differential bias to reach the same value, the instrument indicates the maximum difference between the value, probably said that the instrument in a strong external conditions, the measured Parameters from small to large change (positive characteristics) and the measured parameters from large to small change (reverse characteristics) is not uniform degree, the difference between the two is the instrument deterioration. Reliability Weighing control instrument reliability is the chemical industry instrument workers to seek another tension performance indicators. Reliability and instrument maintenance is the opposite phase, the instrument reliability is high to clarify the instrument maintenance is small, otherwise the instrument reliability is poor, the instrument maintenance is large. To deal with chemical enterprise testing and process control instruments, most of the placement in the process of pipeline, all kinds of towers, kettle, cans.
Weighing the sensitivity of the instrument occasionally also known as "magnification ratio", but also the static characteristics of the instrument on the slope of the points on the line. Increasing the magnification can increase the sensitivity of the instrument, simply increase the sensitivity does not change the instrument's basic performance, that is, weighing the accuracy of the instrument did not improve, on the contrary there will be signs of oscillation, resulting in unstable output. Instrument sensitivity should be tied to the appropriate amount.