In the use of field instruments, switching and analog are the two most commonly used input and output methods. Today, we will use a combination of pictures and texts to explain in detail what the principle of switching and analog quantities is. Switching quantity

Figure 1 shows a typical switching signal pressure representation intent. When the pressure is high, the two contacts C and B are closed and connected, and the output pressure is high signal, and when the pressure is low, the two contacts C and A are closed and turned on to output the low pressure signal. Here C and B are a switch, and C and A are also a switch. So a switching contact is a switching quantity, and its characteristic is that it is either turned on or off at the same time. Turning on is 1, which means that there is a signal, and disconnecting is 0, which means that there is no signal. This is known as a switching signal. With such a switching signal, the local pressure signal can also be transmitted to the control center to participate in automatic remote control. However, it only transmits a signal such as whether there is pressure or not, and it is impossible to know what the real-time pressure value is. Analog

The instrument in Figure 2 is a pressure transmitter, which can solve the problem of remote transmission of pressure values above. Inside the pressure transmitter there is a circuit board to which the pressure sensor F is connected. The working principle of the pressure transmitter is that the pressure sensor F transmits the detected pressure to C of the circuit board, and after the detection signal enters the circuit board, the pressure signal is converted into a current signal and output by the two points of A and B through the conversion and calculation of the circuit board. The right side of the figure is a schematic diagram of the pressure transmitter signal conversion, which can convert a 0-10kpa pressure signal into a 4-20mA current signal, which is output by two points, A and B. At this time, we say that the pressure transmitter says that the two points A and B output an analog signal. The characteristic of an analog signal is that its value is continuously variable over a range of values. If you have any questions about product consultation, product customization, agency, technical inquiry, quotation, etc., please contact Xingyi: 400-600-4496!