What are the three kinds of thermal resistance of the wire mainly?

What are the three kinds of thermal resistance of the wire mainly? Two wire: in the heat resistance at each end of a petition to elicit resistance signal way is called a wire two wire: this method is simple, lead but there because a petition wire must lead resistance r, r size and material of the wire and the length of the factors, because the means of this kind of lead is only suitable for use in surveying at a lower precision; Three wire system: at one end of the thermal resistance of the roots petition a lead, on the other side of the two period leads the way called three wire system, and a bridge composed of a set of commonly use this way, you can better eliminate the influence of the lead resistance, is commonly used in industrial process stem lead resistance; Four wire: in the root systems of thermal resistance on both ends of the two period known as the four wire, wire way which leads to supply heat resistance with two eternal fixed current I, R U change into voltage signal, again through the other two root lead to guide U to secondary instrument. See this way can eliminate lead pure lead resistance, mainly used for high precision temperature testing. www。 wuxiyibiao。 com