Pressure transmitter is mainly composed of pressure element sensor (also known as pressure sensor), measuring circuit and process connector. It can convert the physical pressure parameters such as gas and liquid sensed by pressure sensor into standard electrical signals (such as 4-20 mADC) to supply secondary instruments such as indicator alarm, recorder and regulator for measurement, indication and process adjustment control. Pressure transmitters can be divided into general pressure transmitters (0.001MPa-35MPa) and differential pressure transmitters (0-1.5kPa), negative pressure transmitters according to the measurement range. In terms of accuracy, pressure transmitters can also be classified as high precision pressure transmitters (0.1% or 0.2% or 0.07) in recent years because the accuracy of our national standard is 0.5% F.S. 5% and general pressure transmitter (0.5%).

Friends in the industry all know that pressure transmitter is an automatic control front-end component used to detect fluid pressure (actually pressure), and can carry out remote signal transmission, signal transmission to secondary instrument or computer for pressure control or monitoring. It has a very important role in the field of industrial control. Widely used. Current situation of pressure control technology in domestic compressor industry: At present, low-cost pressure switch is generally used for simple pressure control in domestic small compressors. Its main characteristic is low cost. Pressure transmitters are mostly used in domestic large compressors and screw compressors. The advantages of using pressure transmitter for pressure control are: realizing multi-point control, setting conveniently, using pressure transmitter, the pressure signal detected is continuous signal, so the pressure point can be set arbitrarily, and it is very convenient to set. There is no need to adjust the pressure transmitter, only setting up the electric control part to realize compressor operation. After using pressure transmitter to prolong compressor life, advanced compressor operation control can be realized, which makes compressor run more smoothly. At the same time, if frequency conversion technology is applied, compressor start times can be greatly reduced, compressor life can be prolonged, and energy-saving can be achieved. At the same time, the pressure transmitter uses non-mechanical sensing elements, so it basically does not need maintenance, and the damage rate is very low. Because the detection accuracy of the pressure transmitter is several times higher than that of the pressure switch, the control accuracy has been greatly improved.

In the control system of air compressor, the pressure transmitter installed in the outlet pipe of the back end of air compressor is used to control the pressure of air compressor. When the air compressor starts, the loading solenoid valve is closed, the loading cylinder does not move, and the frequency converter drives the motor to run without load. After a period of time, the loading solenoid valve opens and the air compressor runs with load. When the air compressor starts to run, if the compressed air pressure in the storage tank and the back-end pipeline does not reach the upper limit of the pressure, the controller acts to load the valve, opens the intake port, and the motor loads, and continuously generates compressed air to the back-end pipeline. If the back-end gas equipment stops using gas, the compressed pressure in the back-end pipeline and storage tank gradually increases. When the upper limit of pressure is set, the pressure transmitter sends out the unloading signal, the loading solenoid valve stops working, the intake filter closes, and the motor runs without load. When the air compressor is running continuously, the main body temperature of the compressor will rise. When the temperature reaches a certain level, the system is set to 80 C (which can be set by the controller according to the application environment) and the fan starts to run, which is used to reduce the working temperature of the main engine. When the fan runs for a period of time, the temperature of the main engine decreases and the fan stops running below 75 C.

The working principle of PepsiCo DPI701 pressure transmitter is polysilicon sensor, which can output standard 4-20mA analog signal through resistance-current conversion, temperature compensation, linear correction and data processing. The unique leak-free technology is one of the highlights of the product. It works stably and reliably, and has a long service life. Because of its high cost performance, compact size, high precision and high sensitivity, the product has been widely used in high-demand air compressor systems.

DPI701Pressure Transmitter