Introduction
The torque sensor is a precision measuring instrument for measuring various torques, speeds and mechanical power. It has a wide range of applications. In alumina production enterprises, it is mainly used to detect the torque of the driving device of the settling tank rake machine. It is a very important measurement and protection parameter of the settling tank rake machine. To ensure the safe operation of the settling tank rake machine, the DCS sends an alarm signal when the torque is abnormal, and the DCS interlocks to protect the rake machine from stopping when the protection setting value is reached. In the actual production process, the torque sensor itself often causes false alarms and malfunctions of the equipment due to inaccurate measurements, thereby causing unnecessary equipment failures and causing great impact on production. How to judge the performance of the torque sensor? This article introduces the method of using a hanging code to load and detect and judge the performance of the torque sensor.
1  Measurement principle of torque sensor
The more mature detection method for torque measurement is strain gauge electrical measurement technology, which has the advantages of high accuracy, fast frequency response, good reliability and long life. The measurement principle of the strain gauge torque sensor: the strain gauge electrical measurement technology is used to paste the strain gauge on the elastic shaft to form a measuring bridge. When the elastic shaft is slightly deformed by torque, the resistance value of the bridge arm changes. The change in the resistance of the three arms of the strain bridge is converted into a change in the voltage signal, thereby measuring the torque.
2  Torque sensor detection device
2.1  Detection device
The steel detection bracket is made of steel materials such as angle steel and channel steel. A channel steel is fixed on the bracket as a fixed plate. Two holes with a diameter of 6mm are opened at both ends of the fixed plate, which are used to fix the counterweight and torque sensor respectively. The counterweight plays a balancing role when the torque sensor is detected to prevent the detection device from tipping over due to uneven force. The other end of the sensor is connected to the weight tray, and the detection weight can be loaded on the tray. The weight uses a 20kgM1 standard weight.
2.2  Detection instrument
The torque sensor output signal detection uses the ConST318 intelligent process calibrator produced by Beijing Const Instrument Technology Co., Ltd. The instrument can measure the torque sensor output mA signal and provide the sensor with a 24V stable power supply. Its measurement accuracy is 0.01 level and its output accuracy is 0.02 level. The upper half of the calibrator display shows the measured value, and the lower half shows the output value. The navigation key can be used to select the area to be operated. The left area on the top of the calibrator is the measurement signal jack, and the right side is the output signal jack.
The performance test of the torque sensor using the weight loading method can determine whether the torque sensor performance is good, and replace the unqualified torque sensor in advance, which can avoid unnecessary production accidents caused by the torque sensor device error. It is one of the important means to ensure accurate torque measurement. In addition, the performance test of the torque sensor using the weight loading method is practical and simple, with strong practical operability, and has achieved good results in practice.