According to the weighing principle, the instantaneous flow rate of the material measured by the load cell depends on two parameters, that is, the instantaneous flow rate is equal to the material load value q (kg/m) on the load cell measured by the load cell and the belt measured by the speed sensor. The velocity value v(m/s) is multiplied by two parameters. It can be seen that the measurement accuracy and stability of the speed sensor are as important as the measurement accuracy and stability of the load cell. At present, the accuracy of the load cell is generally increased to a few ten thousandths, and the accuracy of the speed sensor is mostly in the thousands of parts, so improving the accuracy of the speed sensor is one of the ways to improve the accuracy of the electronic belt scale system.

After the pulse signal of the speed measuring sensor enters the display instrument, the multiplication operation with the load cell signal is usually completed in three ways. The first way is that the speed measurement pulse signal is transformed into a 0~10VDC analog signal after being shaped and amplified, and is used as a bridge voltage of the load cell to realize multiplication operation in the load cell; the second method is that the speed measurement pulse signal is shaped. After amplification, it is converted into an analog (or digital) signal, and the analog (or digital) signal amplified by the load cell is multiplied in a dedicated multiplier; the third way is to directly measure the speed pulse signal as a display instrument. The accumulator trigger signal, each time receiving a speed measurement pulse signal, the accumulator performs a sampling on the input signal of the symmetric weight sensor. The faster the belt speed, the more the number of times the accumulator samples, the sample values are continuously accumulated, and thus the digital method is implemented. Multiplication operation.

In the process of using the load cell, there are many problems involving the speed sensor, but since there is very little information on this aspect, users often have no way to deal with these problems. The author enumerates some solutions to problems based on his experience and experience in his work, hoping to learn from readers' solutions to such problems. The speed sensor used on the electronic belt scale mainly has two types of magnetoresistive pulse type and photoelectric pulse type. The analog tachogenerator type speed sensor is no longer used, and instead of the above two digital speed sensors for outputting pulse signals.