The economical pressure transmitter is the main instrument for measuring the pressure value in the industrial field. It has the characteristics of high precision, stable measurement and convenient installation. It has the remote transmission control function compared with pressure gauges.
One of the technical parameters of the economical pressure transmitter is the measurement error. The measurement error (also called measurement accuracy) is generally to be 0.075%, 0.1%, 0.2%, 0.5%. How to distinguish the difference between these errors? What are the factors that affect the error performance of economical pressure transmitters?
When calculating the total error of an economical pressure transmitter, the defined error should be used. The main reasons caused errors are as follows:
1. The pressure guiding tube and the process pipeline are not tightly connected, resulting in leakage of gas or liquid in the pipeline.
2. Wear loss occurs when using a cleansing agent.
3. Indenter error caused by three reasons: there are gas in the liquid pipeline; liquid in the gas pipeline and different density caused by the temperature difference between the two pressure guiding tubes.
4. No clearing work is performed before the installation and measurement.
So how to solve these errors? Here are some ways as follows:
1. Pay attention to the tightness of the connection between the pressure guiding tube and the process pipeline.
2. When using the cleansing agent, the connection of the cleaning agent should be close to the pressure tap of the process pipe. The length and diameter of the pipeline through which the cleaning agent passes should be the same. The cleaning agent should be prevented from passing through the pressure transmitter.
3. If conditions permit, the pressure guiding tube is as short as possible, .
4. When measuring liquid or steam, the pressure guiding tube is connected upwards to the process pipeline, and its slope should be no less than 1/12.
5. When measuring the gas, the pressure guiding tube is connected downwards to the process pipeline, and the slope should be no less than 1/12.
6. There should be no gas in the pressure guiding tube filled with liquid.
7. In order to avoid the influence of friction, the diameter of the pressure guiding tube should be big enough.