3.2　Temperature

3.2.1　The temperature measuring element shall be installed at the position where the measured value is able to indicate the temperature of the measured medium，but it shall not be installed at the dead corner of pipeline and equipment.

3.2.2　When measuring the temperature of such equipment and pipeline with relatively large volume，the multi-point sampling mode should be adopted and then the averaging should be implemented.

3.2.3　The area where the temperature measuring element is installed shall not be affected by any fierce vibration and resonance.When installing the socket of temperature element on the medium-and lowpressure high-flow pipeline，the conduit shall be installed or the protection measures shall be taken at the upstream.

3.2.4　Where the thermocouple or thermal resistance is installed at concealed place or the position where is inaccessible during the operation of the unit，then its terminal shall be led to the place where is easy to access.

3.2.5　The material of the protective sleeve and socket of thermocouple or thermal resistance shall meet the requirements of the measured medium and its parameters.

3.2.6　The socket and protective sleeve of temperature measuring element shall be installed before the pressure test of thermal system and shall be involved in the sealing test of the main equipment.

3.2.7　The installation of temperature measuring element shall meet the following requirements：

1　Before installing the screw-fixed temperature measuring element，the screw thread tolerance size of the socket and the measuring element shall be measured；

2　The internal oxide layer of the temperature socket shall be cleared off，and the screw thread shall be coated with anti-rust or anti-jam material；

3　Sealing gasket shall be installed between the temperature measuring element and the socket，and the tightness of the contact surface after installation shall be ensured；

4　As for the high-and medium-pressure pipelines，if the whole socket is in the insulating layer，then floppy thermal insulating material should be adopted to make thermal insulation outward starting from the end surface of socket，and the socket height should not be less than the insulating layer thickness.

3.2.8　As for the horizontally-installed temperature measuring element，if the insertion depth is larger than 1m，proper measures shall be taken to prevent the protective sleeve from bending.

3.2.9　The temperature measuring element installed on air-powder pipe shall be set with the anti-abrasion protective cover（can be dismantled together with the temperature measuring element）or other antiabrasion measures.

3.2.10　When installing the temperature measuring element on the pipeline with diameter less than 76mm，if the insertion depth of the temperature measuring element is greater than diameter of the pipeline，then an enlarged pipe should be installed additionally.

3.2.11　When installing the temperature measuring element on such pipeline of which the nominal pressure is equal to or less than 1.6MPa，the measuring element may be inserted at the elbow along the center line of pipeline，facing the flow direction of medium.

3.2.12　The bimetal thermometer shall be installed at the place where is convenient for monitoring and is uneasy to suffer from any mechanical damage，and its temperature sensing element shall be wholly immersed into the measured medium.

3.2.13　The bulb of pressure-type thermometer shall be wholly immersed into the measured medium.The protection measures shall be equipped for the laying of the capillary，the bending radius of capillary shall not be less than 50mm，and heat insulation measures shall be equipped for the capillary when passing through the area whose temperature is relatively high or highly variable.

3.2.14　As for the sleeves of the insertion-type thermocouple and thermal resistance，their insertion depths shall meet the following requirements：

1　If the nominal diameter of high-pressure and high-temperature（main）steam pipeline is not larger than 250mm，the insertion depth should be 70mm；if the nominal diameter is larger than 250mm，the insertion depth should be 100mm；

2　If the outside diameter of general fluid medium pipeline is not larger than 500mm，the insertion depth should be 1/2 of the outside diameter of pipeline；if the outside diameter is larger than 500mm，the insertion depth should be 300mm；

3　As for the flue gas，air and air-powder mixture pipelines，the insertion depth should be 1/3～1/2 of the outside diameter of pipeline；

4　On the oil return pipeline，the measuring end of temperature measuring element shall be immersed into the measured medium.

3.2.15　The temperature measuring element used for measuring the temperature of pulverized coal in pulverized coal hopper should be inserted vertically from the top of the hopper and shall be taken with antiabrasion and anti-bending reinforcement measures，its insertion depth should be divided into three kinds：upper，middle and lower；therefore，it is able to measure the temperature of pulverized coal at different cross sections.

3.2.16　The temperature measuring element installed on high temperature or high pressure steam-water pipeline shall be perpendicular to the center line of the pipeline.

3.2.17　The temperature measuring element for the inner cylinder of steam turbine shall be firmly installed，the fasteners shall be tightly locked，and the temperature measuring element shall be convenient for dismantling，the outgoing part shall be free from any leakage.

3.2.18　As for the temperature measuring element for measuring the metal temperature，its measuring end shall be tightly close to and well contacted to the measured surface；if the measured surface has insulation facilities，then the temperature measuring element shall be insulated together.

3.2.19　The measuring end of such thermocouple for measuring the pipe surface temperature of boiler superheater and reheater should be installed at the vertical pipe section within 100mm above the roof pipe.Where the boiler structure disallows，the installation position of measuring end may be moved upward appropriately，but the elevation of those measuring points installed on the same superheater or reheater shall be consistent，and the welding work shall be carried out before the hydraulic test.

3.2.20　As for the thermocouple for measuring the wall temperature of steam lead pipe before steam turbine，its measuring end shall be installed at the lower part of horizontal pipe section.

3.2.21　The installation position and insertion depth of the waterproof temperature measuring element of steam turbine shall meet the requirements of design or manufacturer.

3.2.22　The sheathed thermocouple that has been installed for measuring the pipe surface temperature shall have the measures to prevent damages caused by the on-site subsequent construction.

3.2.23　As for the standby temperature measuring element for measuring the bearing bush temperature of steam turbine，its lead wire shall be led to the junction box.