Two-wire advantages: 1, less susceptible to parasitic thermocouples and pressure drop along the wire resistance and temperature drift, can be used very cheap finer wire; can save a lot of cable and installation costs; 2, when the current source output resistance is enough large, the magnetic field sensor coupled to the voltage of the wire loop will not have a significant impact, because the current source of interference caused by small, usually using twisted pair can reduce the interference; three-wire and four-wire shielded cable must be used shielding layer shielded cable should be properly grounded. 3, capacitive interference can cause the receiver to the transmitter temperature resistance of the error, for 4 ~ 20mA two-wire loop, the receiver resistance typically 250Ω (sampling Uout = 1 ~ 5V) that resistance small enough to produce significant errors Therefore, you can allowed wire length longer than the voltage telemetry system; 4, each time a single display device or recording device can be connected to the exchange wire length ranging between different channels, and not by varying the length of the wire between accuracy, decentralized collection, decentralized capture advantage is: decentralized collection, centralized control .... 5, 4mA to zero level, so that the judge open and short circuit or sensor damage (0mA state) is very convenient. 6, two-wire output port is easy additional twelve lightning protection and surge device, is conducive to safe mine explosion. Hua Hui Technology is a professional development, production DMP9051 multi-parameter transmitter manufacturer STT171 temperature transmitter, this new integrated differential pressure flow transmitter is a set of differential pressure transmitters, temperature transmitters , pressure transmitter, flow totalizer in one of the new transmitter, can display the working pressure, temperature, instantaneous, cumulative flow, you can replace the original by the differential pressure transmitter (Intelligent differential pressure transmitter, differential pressure transmitter), the traditional flow meter measurement unit pressure transmitter, temperature transmitter, the second instrument. And gas, steam and other media for automatic temperature and pressure compensation calculation, realized the scene directly display honeywell_ standard conditions and mass flow temperature transmitters, DMP9051 multi-parameter transmitter to 24V, built-in lithium dual power supply work inlet temperature transmitter, built-in lithium battery can work in case of power failure - three years in the case of an external 24V power supply can provide current, frequency, 485 remote output. Temperature transmitters, temperature transmitters, China-Technology provided by the Jinan-Technology Co., Ltd. Jinan Huahui Technology Co., Ltd. (www.cnhuahui.com/) strong, credible, in Jinan, Shandong pressure instrumentation industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead China-Technology into the brilliant and you work for a better future!