What are the wiring methods of the pressure sensor?

The wiring of the sensor has always been one of the most frequently asked questions in the customer procurement process. Many customers do not know how to connect the sensor. In fact, the wiring methods of various sensors are basically the same. Pressure sensors generally have two-wire, three-wire, Four-wire system, and some have five-wire system.
The two-wire system of the pressure sensor is relatively simple. Generally, customers know how to wire it. One line is connected to the positive pole of the power supply, and the other line is the signal line, which is connected to the negative pole of the power supply through the instrument. On the basis of the wire system, a wire is added, and this wire is directly connected to the negative pole of the power supply, which is a little more troublesome than the two-wire system. The four-wire pressure sensor must have two power input terminals, and the other two are signal output terminals. The four-wire system is mostly voltage output instead of 4~20mA output, and the 4~20mA is called a pressure transmitter, most of which are made of two-wire system. The signal output of some pressure sensors is not amplified, and the full-scale output is only tens of millivolts, while some pressure sensors have internal amplification circuits, and the full-scale output is 0~2V. As for how to connect to the display instrument, it depends on the range of the instrument. If there is a gear suitable for the output signal, it can be directly measured, otherwise a signal adjustment circuit must be added. The five-wire pressure sensor is not much different from the four-wire system, and there are relatively few five-wire pressure sensors on the market.
thread type
There are many kinds of threads for pressure sensors, and the common ones are NPT, PT, G, and M, all of which are pipe threads.
NPT is the abbreviation of National (American) Pipe Thread, which belongs to the 60-degree tapered pipe thread of the American pressure sensor standard and is used in North America. National standards can be found in GB/T12716-1991
PT is the abbreviation of Pipe Thread. It is a 55-degree sealed tapered pipe thread. It belongs to the Wyeth pressure sensor thread family. It is mostly used in Europe and Commonwealth countries. It is often used in the water and gas pipe industry, and the taper is 1:16. National standards can be found in GB/T7306-2000
G is a 55-degree non-threaded sealing pipe thread, which belongs to the family of Whitworth pressure sensor threads. Marked as G stands for cylindrical thread. National standards can be found in GB/T7307-2001
M is a common metric thread. For example, M20*1.5 means that the diameter is 20mm and the pitch is 1.5. If the customer has no special requirements, the pressure sensor is generally M20*1.5 thread.
In addition, the 1/4, 1/2, and 1/8 marks in the thread refer to the diameter of the thread size, and the unit is inch. People in the industry usually use points to refer to the thread size, one inch is equal to 8 points, 1/4 inch is 2 points, and so on. G seems to be the collective name for pipe threads (Guan). The division of 55 and 60 degrees is functional, commonly known as pipe circle. The thread is machined from a cylindrical surface.
ZG is commonly known as pipe cone, that is, the thread is processed by a conical surface. The general water pipe pressure joint is like this. The old national standard is marked as Rc
The metric thread is represented by the pitch, and the American and British thread is represented by the number of thread teeth per inch. This is the biggest difference between the pressure sensor thread. The metric thread is a 60-degree equilateral tooth type, and the British system is an isosceles 55-degree tooth type. American thread 60 degrees. Use metric units for metric threads and imperial units for US and British threads.
Pipe thread is mainly used for the connection of pressure pipes, and its internal and external threads are closely matched. There are two types of pressure sensor pipe threads: straight pipe and tapered pipe. The nominal diameter refers to the diameter of the connected pressure pipe, obviously the major diameter of the thread is larger than the nominal diameter. 1/4, 1/2, 1/8 are the nominal diameters of British thread, in inches.