The editor found the selection rules of pressure transmitters on the Internet 1. According to the type of pressure to be measured The pressure types mainly include gauge pressure, pressure and differential pressure. Gage pressure is a pressure less than or greater than atmospheric pressure based on the atmosphere; pressure is above the pressure at the zero position of pressure, and differential pressure is the difference between two pressures. 2. According to the measured pressure range Under normal circumstances, the actual measurement pressure is 80% of the measurement range. The high pressure of the system should be considered. Generally speaking, the pressure range of the pressure transmitter should reach 1.5 times the system pressure. Some water pressure and process controls have pressure spikes or continuous pulses. These peaks can reach 5 or even 10 times the pressure, which can cause damage to the transmitter. Continuous high pressure pulses, approaching or exceeding the maximum pressure rating of the transmitter, will shorten the actual life of the transmitter. But increasing the pressure rating of the transmitter sacrifices the resolution of the transmitter. Buffers can be used in the system to reduce spikes, which can slow down the response of the sensor. Pressure transmitters are typically designed to withstand 200 million cycles without degrading performance. When selecting a transmitter, we can find a compromise solution between system performance and transmitter life. 3. According to the measured medium According to the different measuring medium, it can be divided into dry gas, gas-liquid, highly corrosive liquid, viscous liquid, high-temperature gas-liquid, etc. Correct selection according to different media is beneficial to prolong the service life of the transmitter. 4. According to the super overload of the system The super overload of the system should be less than the overload protection limit of the transmitter, otherwise it will affect the service life of the transmitter and even damage the transmitter. The safe overload pressure of the pressure transmitter is generally twice the full scale. 5. According to the required accuracy level The measurement error of the transmitter is divided according to the accuracy level, and different accuracies correspond to different basic error limits (expressed as a percentage of the full-scale output). In practical application, according to the control requirements of measurement error and the principle of economical use. 6. According to the working temperature range of the system The temperature of the measuring medium should be within the working temperature range of the transmitter. If it is used over temperature, a large measurement error will occur, which will affect the service life of the transmitter; in the production process of the pressure transmitter, the temperature influence will be measured and compensated to ensure that the measurement error caused by the temperature influence is within the accuracy within the level. When the temperature is high, we can consider choosing a high temperature pressure transmitter or taking auxiliary cooling measures such as installing a condenser pipe and a radiator. 7. According to the compatibility of the measurement medium and the contact material, in some measurement occasions, the measurement medium is corrosive, so it is necessary to select a material compatible with the measurement medium or perform special processing to ensure that the transmitter will not be damaged. 8. According to the form of pressure interface Usually threaded connection (M201.5) is the standard interface. 9. According to the on-site working environment and other Whether there is vibration and electromagnetic interference, etc. The selection should provide relevant information so that appropriate action can be taken. When selecting, other methods such as electrical connection can also be considered according to specific circumstances.