1, for liquid level continuous measurement, differential pressure transmitter is recommended.

For interface measurement, we can choose differential pressure transmitter, but liquid level should always be higher than tapping point.

2, in normal conditions, when liquid density have obvious changes, unfavorable choose differential pressure instrument is not recommended.

3, For corrosive liquid, crystalline liquid, liquid viscous resistance, easy gasification liquid, including suspended substance liquid ,we can choose flat flange differential pressure transmitter.

For High crystallization of liquids, high viscosity liquids, and colloidal liquid, precipitation liquid, we can choose insertion flange differential pressure transmitter.

If gas phase has a large number of condensate, sediment precipitation, or need will be high temperature liquid and the transmitter isolation, or replace measured medium, need to strictly purification measuring point,we can choose double flange differential pressure transmitter.

4, For corrosive liquid, sticky liquid, crystalline liquid, melting property liquid, precipitation liquid , when we have low demand for the measurement accuracy, we should use air blowing or impact liquid method, together with differential pressure transmitter to take measurement.

5, in the environmental temperature, the gas phase may condenser, liquid may vaporizing, or gas phase liquid separation, when use ordinary differential pressure transmitter measurement, condensing vessels, separate containers, balance container etc, need to be used. or we should take methods of insulation or heat tracing.

6, we should take into consideration positive, negative transfer within instrument range, when we choose differential pressure instruments.