The transmitters we choose, whether they are pressure transmitters, liquid level transmitters, temperature transmitters, or differential pressure transmitters, require the measurement results to be converted into standard signals in order to be transmitted to control and display devices. The two wire system is relative to the four wire system (two power lines, two communication lines), which combines the power line and signal line into one. The transmitter adopts a two wire system, which means that the on-site transmitter is only connected to the control room instrument using two wires, which are both power lines and signal lines. Today we will talk about the advantages of using a two wire output system for transmitters. The advantages of using a two wire system for transmitters: Firstly, transmitters using a two wire system are less susceptible to the effects of parasitic thermocouples (the electromotive force generated by connecting two different conductors, which are parasitic in the circuit) along the wire resistance voltage drop and temperature drift. In this way, we have no special requirements for the wires used, which can save cable costs. Secondly, capacitive interference during the use of the transmitter can lead to receiver resistance related errors. For a 4-20mA two wire loop, the receiver resistance is usually 250 Ω (sampling Uout=1-5V), which is too small to produce significant errors. In this case, the transmitter can allow a longer and farther wire length than the voltage telemetry system; Thirdly, when the output resistance of the current source is large enough, the voltage inside the wire loop induced by magnetic field coupling will not have a significant impact, because the current caused by the interference source is extremely small. Generally, twisted pair cables can be used to reduce interference. However, for three wire and four wire transmitters, shielding wires must be used, and the shielding layer of the shielding wire must be properly grounded. Fourthly, it is very easy to add one or two lightning and surge protection devices to the output port of the transmitter using a two wire system, which is beneficial for the safe lightning and explosion protection of the transmitter. If you have any questions regarding product inquiries, product customization, agency, technical inquiries, quotations, etc., please contact Xingyi at 400-600-4496!