What is the mode explosion-proof thermocouple installed correctly _ instrument

Thermocouple is its resistance is a function of temperature, the temperature changes its resistance is also changing. According to its resistance value at 25 degrees, divided into PT - thermocouple 100年,PT - 50岁的PT - 1000, etc. When a thermocouple is used to measure the temperature will have to pass a bridge resistance change into voltage changes. Thermocouple at both ends of the voltage is a function of temperature, the temperature changes its dc voltage is also changing. Depending on the anode materials are divided into T ( Copper - Constantan) , K type ( Nickel chrome - Nickel aluminum) , J, S, etc. Explosion-proof thermocouple installation right first before we installed correctly, to understand the principle and structure, in order to facilitate understanding, so as to better installed correctly. Explosion protection of thermocouple thermocouple with special structure of the junction box, 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. Reed explosion-proof thermocouple technique parameter pressure temperature sensing element, ant-vibration performance is good; High measuring accuracy; High mechanical strength, good compression performance; Imported film resistance element, performance stable and reliable; Explosion-proof grade: exd Ⅱ ct4exd Ⅱ ct6exiact4 / exiact6 m20 x 1 degree of protection ip65 electrical exports. 5 1/2? NPT explosion protection thermocouple principle of 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. Explosion-proof thermocouple installation requirements for the installation of the thermocouple, should pay attention to accurate temperature measurement, safety examination and maintenance is convenient, and does not affect the equipment operation and production operations. To meet the above requirements, in the choice of the installation site of the thermocouple and insertion depth should pay attention to the following points: 1, in order to make the measurement end of the thermocouple, and had good heat exchange between the measured medium, should be a reasonable choice of observation, try to avoid the valve, elbow and thermocouple pipeline and equipment near the corner of installations. 2, with a thermocouple with heat transfer and heat loss protection casing, in order to reduce the measurement error, thermocouple and thermocouple should have enough: (insert depth 1) For the measurement of pipeline fluid temperature thermocouple, generally should be measuring end is inserted into the pipe ( Vertical or inclined installation) 。 As the current body of pipe diameter is 200 mm, the thermocouple insertion depth should choose 100 mm; ( 2) For high temperature and high pressure and high velocity of temperature measurement, Such as main steam temperature) , in order to reduce cases of fluid resistance and prevent cases break under the action of a fluid, can take protecting tube shallow inserted way or use hot thermocouple. Shallow inserted type thermocouple protection tube, its depth into the steam pipe should be no less than 75 mm; Heat sets the standard of thermocouple insertion depth is 100 mm; ( 3) If is need to measure the temperature of flue gas, although the flue is 4 m in diameter, thermocouple insertion depth of 1 m. ( 4) When measuring the original insertion depth of more than 1 m, shall be installed vertically, as far as possible or add racks and protect casing.