Thermocouple installation requirements and the installation of thermocouple considerations have those _ instrument

Installation of thermocouple, should pay attention to temperature measuring accurate, safe and reliable and convenient maintenance, and shall 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. Thermocouple installation note 1, the thermocouple should be installed vertically in a horizontal or vertical pipe runs, thermocouple when installation should be protect casing, to facilitate maintenance and replacement. 2, temperature measurement of the pipe, the element length should be on the pipe line ( The protection tube insertion depth should be the half of pipe diameter) 。 3, moving coil temperature table when installation, hole size to fit, install to the beauty is generous. 4, high temperature using high temperature or high temperature compensation cable. 5, according to the different choice of different temperature measuring element. General thermocouple measuring temperature less than 400 ℃ when choice. 6, reasonable wiring to aesthetics, whose hands pointing to correct. Thermocouples are widely used in industrial temperature measurement not only, and is made into standard benchmark instrument. But his due to his temperature measurement range application by certain restrictions, thermocouple temperature measurement principle is based on a conductor or semiconductor resistance changes with the change in temperature. 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. Thermocouple and thermocouple type, but he does not need compensation conductor, and is much cheaper than thermocouple. Platinum thermocouple installation form a lot, have a fixed screw to install, thread installation, fixed flange installation, flange installation, pipe installation, straight pipe connector installation, etc. Thermocouple and the choice of the thermocouple is a big difference in the temperature range of choices, thermocouple is measuring the temperature of the low temperature sensor, measure temperature in commonly - Is 200 ~ 800 ℃, and the thermocouple temperature sensor in measuring high temperature, average temperature in 400 ~ 1800 ℃, when the choice if measuring temperature at 200 ℃ or so, should choose the thermocouple measurements, if the measure temperature in 600 ℃ should choose K type thermocouple, if the temperature of 1200 ~ 1600 ℃ should choose S type or B type thermocouple.