Choose The Right Level Measurement Transmitter To Meet The Needs Of Industrial Automation

As a type of industrial automation instrument, the main function of the level measurement instrument is to measure the level height of liquid and powder granular materials. People usually call the instrument used to measure the stacking height or surface position of solid materials a level meter or liquid level switch; the instrument used to measure the height or liquid level position of liquids is called a liquid level meter; and the instrument used to measure the interface position of two immiscible liquids or solids and liquids in a container is called an interface meter. So, how to choose a suitable level measurement transmitter to better meet the needs of level measurement?

When selecting a level measurement instrument, it is usually necessary to start from the following aspects:

1. If the material surface needs to be measured, it should be selected according to the particle size, repose angle, conductivity, silo structure and measurement requirements of the material. If the liquid surface and interface are measured, vibration instruments, differential pressure instruments, float instruments and float instruments can be selected. If the above instruments cannot meet the needs, you can consider using capacitive, resistive (electric contact), acoustic wave and other instruments.

2. When selecting the type, you should have an in-depth understanding of the process conditions, the properties of the measured medium, and the requirements of the measurement and control system, so as to comprehensively evaluate the technical performance and economic effects of the level detection instrument to ensure the improvement of production stability, product quality and economic benefits.

3. According to the characteristics of the measured medium, select the structural form and material used by the instrument. When selecting the type, you should focus on factors such as the pressure, temperature, corrosiveness, conductivity, density and density change of the measured medium, the amount of suspended matter in the liquid, the degree of liquid surface disturbance, and the particle size of the solid material.

4. When determining the range of the level measurement instrument, it should be set according to the actual demand range or actual change range of the process object. Except for the level instrument for volume measurement, the normal level should generally be about 50% of the instrument range.

5. When determining the display mode and function of the instrument, it should be selected according to the requirements of the process operation and system composition. If signal transmission is required, the instrument with analog signal output function or digital signal output function can be selected as appropriate.

6. The accuracy of instrument measurement should be selected according to process requirements, but for level measurement instruments for volume measurement, the accuracy level should generally be above 0.5.

7. For electronic level instruments used in explosive hazardous places such as flammable gas, steam and flammable dust, appropriate explosion-proof structure types or corresponding protective measures should be selected according to the category of hazardous places and the degree of danger of the measured medium.

8. For electronic level instruments used in places such as corrosive gas and harmful dust, appropriate shell protection types should be selected according to the environmental conditions of the instrument.