1. There are generally some impurities in the medium, the bearing, the shaft to produce wear, so that the gap between the two increases, the dynamic balance of the moving parts is destroyed, the speed decreases, or the dirt enters the gap, the movement resistance increases, the speed decreases. These reasons cause the display value of the instrument to decrease, and there is a negative error, which is unfavorable to the fluid supplier;
2. Fibrous or viscous impurities in the fluid are attached to the rotating part of the flow meter, which increases the rotational resistance, resulting in a decrease in the indicator value of the instrument and a negative error, which is unfavorable to the supplier of the fluid;
3. The fluid temperature, pressure changes may make the liquid in the pipeline to escape the air contained or because the pressure in the pipeline is lower than the saturated vapor pressure of the fluid, so that part of the liquid into steam, may also be due to the negative pressure of the medium so that the outside gas is sucked into the pipeline, these gases with the measured liquid flow, resulting in an increase in the indicator value of the instrument, a positive error, adverse to the demand side of the fluid;
4. The working environment is relatively harsh, such as electromagnetic field interference, dust, high temperature, vibration, humidity, etc., may cause the turbine flow sensor misoperation or failure, directly resulting in the turbine flow meter error, the error is positive or negative, may not be obvious, may also be completely ineffective. For the above phenomenon, when the problem is relatively serious, the problem can be found from the comparison of the working status of the process, and it is easy to take corresponding measures. However, in the early stages of the problem, the problem cannot be detected without taking special measures.
