Electronic belt scale is a measuring device installed on a belt conveyor to continuously and dynamically weigh the materials passing through. It mainly consists of a scale frame, a weighing sensor, a speed sensor, and an instrument. The weighing sensor and the speed sensor are the direct sources for obtaining measurement data. When selecting two sensors, attention should be paid to relevant matters.
(1) Selection of weighing sensors
The weighing sensor should bear the weight of the weighing frame, the weight of the roller group and bracket on the weighing section, the weight of the belt on the weighing section, the influence of tension, and the weight of the material on the weighing section.
The first three items are tare weight, and the latter item is the weight of the material being measured. In general, the belt is relatively large while the material weight is relatively small. During use, regardless of whether the conveyor is running or not, the weighing sensor always bears a large load, which can easily cause premature fatigue of the elastic body of the weighing sensor and damage its accuracy.
If a large-sized weighing sensor is chosen, the weight of the material will be smaller relative to the rated load of the weighing sensor, the resolution of the sensor will be insufficient, the display error will be large, the weighing accuracy will be low, and it will not meet the measurement requirements.
Therefore, when choosing a weighing sensor, it is necessary to choose the characteristics of good fatigue resistance, high impedance, high arch bridge voltage, high sensitivity, and high resolution. Otherwise, the accuracy is either very low or the accuracy is good at the beginning, but the stability is insufficient and it has no practical value.
(2) Speed sensor
The weighing result of the belt scale is the product of weight and speed, and the accuracy of the speed signal is equally important as the weight signal, so the cantilever shaft should be very flexible.
The cantilever of the speed sensor should have a certain length, and the friction wheel should have corresponding weight and flexible rotation.
The outer edge should be covered with a material with a high friction coefficient and good wear resistance to ensure sufficient friction between the friction wheel and the belt, allowing the friction wheel to perform pure rolling without sliding and ensuring the accuracy of the speed signal.
