The selection of pressure and differential pressure transmitter is to consider the requirements of control channel. According to the requirements of control performance, high precision instruments are selected. Among them, the pressure differential pressure transmitter which is used to calculate the thermal balance of test instrument system (KME) is selected with accuracy (0.025%) and better performance.

Second, we should consider the convenience of maintenance. Considering the radiation protection zoning, the instrument should be located in the reachable area, installed on the instrument rack to facilitate maintenance and operation, to meet the requirements of periodic test and instrument calibration. (5) Other matters needing attention. In the selection and design of pressure transmitter, attention should also be paid to the requirements of functional accuracy, response time, post-accident accuracy and consistency of special measuring points in safety criteria.

In addition, explosion-proof should be considered in the presence of flammable and explosive dangerous atmosphere in the instrument environment. Some of the instruments are not safe in the electrical equipment classification list, but they are required to perform functions under earthquake conditions, or the radiation zone of the installation location has a certain radiation dose. In order to ensure the measurement accuracy and stability of the instrument for long-term operation, the pressure transmitter with radiation aging and seismic test is usually considered in the selection of such instruments.