The concrete mixing station uses an automatic dosing system with sensors to greatly improve the accuracy and production speed of concrete. Therefore, the correct selection of the load cell has become the key to improving the accuracy, stability and reliability of the ingredients.
The principle of selecting the weighing sensor for the batching scale can be summarized as follows:
Choose according to the usage environment. The first consideration is the environment in which the sensor is used, because the actual use environment of the load cell is related to its ability to function properly and the operational stability and reliability of the entire batch weighing system.
For humid environments, sensors with better sealing performance should be used, and appropriate measures should be taken to minimize the impact of the environment on the stability of the sensor, ensure the reliability of the batching system, and prolong the service life.
The range of the sensor. After determining the type of sensor, it is necessary to look at its range. Because the sensor's range determines whether it is easy to use and durable. The range of the sensor for the batching system is determined by a series of factors such as the maximum mass of the material to be weighed, the weight of the skin and the number of sensors. Even for the same weighing load, the sensor range is different for different batching scales. .
The range and practical experience of the sensors of the mixing plant at home and abroad should be selected. When the weighing instrument allows, the sensitivity of the sensor should be 2±0.02MV/V, and the full load range of the sensor should be the full scale of the batching scale. 50% to 70%.
The accuracy of the sensor. The choice is based on economic, practical and sensor performance. The higher the accuracy of the sensor, the more expensive it is. The accuracy of the weighing system used in the mixing system of the mixing station is OIML R60#C3.
Sensor sensitivity. When designing the batch weighing system, it should be selected according to the parameters provided by the sensor manufacturer. Now, the sensitivity of the sensor is basically uniform, generally 2 ± 0.02 MV / V.
In the linear range of the sensor, the higher the sensitivity, the better, because the high sensitivity is beneficial to the processing of the signal. However, it should be noted that high sensitivity is susceptible to external interference unrelated to measurement, which affects measurement accuracy. Therefore, the sensor itself should be required to have a high signal-to-noise ratio when selecting, and minimize the interference signal brought in by the outside.
