Explosion-proof thermocouple and thermocouple temperature instrument what is the difference between the _ instrument

Thermocouple is a kind of temperature sensor, it is smaller than the diameter of a prefabricated thermocouple, flexible, good vibration resistance, suitable for installation in the case of prefabricated thermocouple can't install, the company produces the thermocouple used to introduce thermocouple temperature measuring element, therefore, is accurate, sensitive, fast thermal response time, stable quality, long service life, etc. Working principle of the explosion-proof thermocouple using clearance flame-proof principles, design has enough strength of the junction box, and other components, will all produce spark, arc and dangerous parts are sealed in the junction box cavity temperature, when the explosion cavity, can remove from heat and cooling by joint clearance, made after the explosion flame temperature and not reach outside the cavity, thereby for temperature measurement. （ 1) Thermocouple temperature measurement system in general by the thermocouple, connecting wires and display instrument, etc. Must pay attention to the following two points: (1) the thermocouple and the index number of the display instrument must agree (2) in order to eliminate the influence of the connection wire resistance change, must use three wire connection. Specific content see this chapter 3. （ 2) Thermocouple thermocouple is by thermal components ( The resistor body) , wire, insulation materials, stainless steel casing combination solid body, its diameter is commonly from 1 to 8 mm, achieve more xiaoke phi is 0. 25mm。 Compared with conventional type thermocouple, it has the following advantages: (1) small volume, no internal air gap, thermal inertia, small measuring hysteresis; (2) good mechanical properties, resistance to vibration and shock. (3) can bend, easy to install (4) long service life. ( 3) Capillary thermocouple ends thermocouple temperature sensing element resistance wire winding by special processing, close to the face in the thermometer. Compared with general axial thermocouple, it can reflect more correctly and quickly end face of the actual temperature being measured, is suitable for measuring temperature bearing and other parts of the face. （ 4) Flameproof thermocouple junction box flameproof thermocouple with special structure, its shell internal explosive mixed gas by sparks or electric arc resistance such as shadow to the circuit repair is bound to change the length of the wire resistance and impact resistance, resistance to replace the new body is good, if the repair welding, after welding to be calibrated before use. Although thermocouple is widely applied in industry, but because of its temperature range makes his application by certain restrictions, thermocouple temperature measurement principle is based on the conductor or the resistance of the semiconductor characteristics of the changes with temperature changes. Its many advantages, can also remote transmission signal, high sensitivity, strong stability, compatibility and accuracy are better, but you need to power, can't instantaneous measured the change in temperature. Industrial thermocouple usually use Pt100, Pt10, Cu50, Cu100, platinum thermocouple temperature measurement range is generally 200 - below zero 800 ℃, copper thermocouple is 40 to 140 ℃ below zero. As to distinguish the type of thermocouple and thermocouple compensation wire, but it does not need and is cheaper than thermocouple.