有表压型压力变送器、绝对压力变送器、差压变送器、投入/插入式液位变送器、中高温压力变送器 Pressure transmitters include gauge pressure transmitters, absolute pressure transmitters, differential pressure transmitters, input / insertion level transmitters, and medium and high temperature pressure transmitters.
The pressure transmitter is also called a differential transmitter, which is mainly composed of a load cell sensor, a module circuit, a display head, a case and a process connection. It can convert the received pressure signals such as gas and liquid into standard current and voltage signals, and supply them to secondary instruments such as indicator alarm, recorder, and regulator for measurement, instruction and process adjustment. Pressure transmitters are divided according to the measured object:
：表压型压力变送器是以当地大气压作为参考零点的压力变送器 1 Gauge pressure transmitter : Gauge pressure transmitter is a pressure transmitter with local atmospheric pressure as the reference zero
2 Absolute pressure transmitter: Absolute pressure transmitter is a pressure transmitter with vacuum as the reference zero. During use, the reference zero point of the sensor can be adjusted automatically with the change of location and area without correction. The appearance is the same as the gauge pressure transmitter
3 Differential pressure transmitter: The differential pressure transmitter is a pressure transmitter that measures the pressure difference between the two pressure chambers. The differential pressure transmitter has two pressure chambers, "+" and "-". It accepts two pressures as comparison values, and usually uses the larger end as the "+" pressure cavity. Attention: When ordering a differential pressure sensor, please pay attention to a parameter unique to the differential pressure transmitter ----withstand static pressure. For example, when the differential pressure transmitter we applied is in use, the pressure on the "+" pressure end is 10MPa, and the pressure on the "-" pressure end is 10.5MPa, then the differential pressure measured by the transmitter is: 10.5 -10 = 0.5MPa, the static pressure of the transmitter is 10MPa. In the application process, the use of high static pressure and low differential pressure is common at the scene. The static pressure of the differential pressure transmitter ordered should not exceed the withstand static pressure value of the differential pressure transmitter, otherwise it will be easily damaged.
4 Input / plug-in liquid level transmitter: There are two types of liquid level transmitters: input type and plug-in type. There are no differences between the two types, and they both convert the pressure to liquid depth. When the water depth is 1m, the pressure on the transmitter is 10KPa, pay attention when ordering such sensors:
The measured liquid density shall be notified to the production unit
The production unit should be informed when the measuring medium is corrosive
Inform the production unit when the temperature of the measuring medium exceeds -10 ° C and 60 ° C
：针对测量现场环境温度过高或者测量介质温度过高，必须使用中高温压力变送器，该变送器具有较好的零点温度系数和灵敏度温度系数，在温度较高的环境下能够保证测量精度。 5 Medium and high temperature pressure transmitters : For measuring the ambient temperature of the site is too high or the temperature of the measuring medium is too high, medium and high temperature pressure transmitters must be used. This transmitter has a good zero temperature coefficient and sensitivity temperature coefficient. It can guarantee the measurement accuracy under high environment. When ordering this type of transmitter, you must inform the temperature of the measurement medium and the ambient temperature in order to facilitate the producer to respond reasonably.