Thermocouple measures lukewarm principle

Thermocouple is lukewarm component of a kind of feeling, it can change temperature signal into pyroelectricity situation signal, pass what electric measuring instrument expresses to cooperate, can measure a temperature that is measured. Thermocouple measures lukewarm fundamental is pyroelectricity effect. In by two kinds the conductor A of different material is mixed B place comprises close in loop, when two contact of A and B are in different temperature T and To, can produce pyroelectricity power in loop. This is effect of so called Sebeck. Conductor A and B call hot electrode. The one end with higher temperature (T > call the job end (solder together normally) ; The one aspect of the matter with inferior temperature (To > call free end (be in a certain constant temperature to fall normally > . Concern according to pyroelectricity situation and temperature function. Can make thermocouple graduation list. Graduation list gets below the condition that carries temperature To=00C freely. Different thermocouple has diverse graduation list. When data of the 3rd kind of metal is received in thermocouple loop, want this material only the temperature of two contact is identical, the hot electromotive force that thermocouple place produces will keep changeless, do not suffer the 3rd kind of metal to receive the effect into loop namely. Accordingly, measure in thermocouple lukewarm when, can receive a measuring instrument to express, after be being measured so that heat up electromotive force, can know the temperature of the medium that be measured. From theoretic tell, two kinds of any conductor can make up thermocouple, but not be all material can make thermocouple actually, reason must satisfy the following to heating up electrode material: (Taller hot electromotive force can arise after 1) thermocouple material suffers temperature effect, the relation between pyroelectricity situation and temperature had better show linear or the only cost function of approximate linear concerns; (2) can measure higher temperature, and in wider temperature a person operating from within in coordination with outside forces uses model country, classics is long-term after using, physics, chemical function and pyroelectricity character keep stable; (The resistor temperature coefficient of 3) requirement material wants small, resistor rate is high, electric performance is good, thermal capacity wants small; (4) reproduction sex is close friends, facilitate large quantities of production and crossing-over, facilitate make uniform graduation list; (5) mechanical performance is good, material is qualitative even; (6) is resourceful, low-cost. CNC Milling