Customer Senvice Hotline
What is the manufacture and accuracy of the weighbridge manufacturer?
Nowadays, the electronic truck scale is more and more popular. How to repair and maintain the electronic truck scale? Let's talk about it from the weighing machine manufacturer:
The electronic truck scale is mainly composed of three parts: sensors, structural parts and circuits. For Class III with accuracy from 1/1500 to 1/10000, the use of double integral A/D conversion circuit can meet the accuracy requirements and has the advantages of strong anti-interference capability and low cost. In the implementation of national measurement regulations, the manufacturer and user should pay attention to the error of electronic truck scale itself and the additional error in use.
1、 Methods of Reducing Error in Design and Production of Electronic Weighbridge
1. Guarantee of sensor technical indicators
It is the key to ensure the quality of electronic truck scale to select the sensors whose technical indicators meet the accuracy requirements. Linearity, creep, no-load temperature coefficient and sensitivity temperature coefficient are important indicators of the sensor. For each batch of sensors, sampling inspection and high and low temperature tests must be carried out according to the sampling rate required by relevant national standards.
2. Temperature coefficient of electronic truck scale circuit
Theoretical analysis and experiment prove that the temperature coefficient of input resistor and feedback resistor of input amplifier is an important factor affecting the sensitivity temperature coefficient of electronic truck scale, and the temperature coefficient must be 5 × 10-6. High temperature test must be carried out for each electronic truck scale produced. For some products with a small amount of temperature coefficient out of tolerance, the temperature coefficient less than 25 can be used × 10-6. At the same time of high temperature test, the product was temperature aged to improve the stability of the product.
3. Nonlinear compensation of electronic scale
Under ideal conditions, the digital quantity of the electronic truck scale after analog digital conversion and the weight imposed on the electronic truck scale should be linear. During the production process, when the accuracy is calibrated, the internal computer program is used for single point correction. Calculate the slope of the number and weight according to the ideal straight line and store them in the memory. It is impossible to overcome the nonlinear errors caused by sensors and integrators. By using multipoint correction and using multiple lines to approximate a curve, the nonlinear error is effectively reduced without increasing the hardware cost. For example, the electronic truck scale with 1/3000 accuracy adopts 3-point correction, and the electronic truck scale with 1/5000 accuracy adopts 5-point correction.