是一种测量中低温度的现场检测仪表。 Bimetal thermometer is a kind of on-site detection instrument for measuring low and medium temperature. It can directly measure the temperature of liquid vapor and gas medium in the range of -80 ℃-+ 500 ℃ in various production processes. 主要的元件是一个用两种或多种金属片 The main component of the industrial bimetal thermometer is a two or more metal sheet
Multi-layer metal sheets laminated together work on the principle that two different metals expand differently when the temperature changes. It is based on a bimetal sheet wound into a loop shape. When one end is heated and expanded, the pointer is driven to rotate, and the working instrument displays the thermoelectric potential.
The desired temperature value.
的安装,应注意有利于测温准确,安全可考及维修方便,而且不影响设备运行和生产操作.要满足以上要求在选择对热电阻的安装部位和插入深度时要注意以下几点: For the installation of bimetal thermometers , attention should be paid to the accuracy of temperature measurement, safety, convenience and maintenance, without affecting the operation and production operations of the equipment. To meet the above requirements, pay attention to the following when selecting the installation location and insertion depth of the thermal resistor A few points:
1.In order to allow sufficient heat exchange between the measuring end of the thermal resistance and the measured medium, the location of the measurement point should be selected reasonably, and thermal resistance should not be installed near the dead corner of the valve, elbow and pipeline and equipment.
2.The thermal resistance with protective sleeve has heat transfer and heat dissipation loss.In order to reduce the measurement error, the thermocouple and thermal resistance should have sufficient insertion depth:
For the thermal resistance of the temperature of the fluid in the center of the pipeline, the measuring end should generally be inserted into the center of the pipeline (vertical installation or inclined installation). If the diameter of the pipeline of the fluid to be measured is 200 mm, the depth of the thermal resistance insertion should be 100 mm ;
For temperature measurement of high-temperature, high-pressure, and high-speed fluids (such as main steam temperature), in order to reduce the resistance of the protective sleeve to the fluid and prevent the protective sleeve from flowing in the stream
If a fracture occurs under the action of a body, the protection tube can be shallow-inserted or a heat-sleeve thermal resistance. The shallow-insertion thermal-resistance protective sleeve should be inserted into the main steam pipe at a depth of not less than 75mm; Insertion depth is 100mm;
If it is necessary to measure the temperature of the flue gas in the flue, although the flue diameter is 4m, the thermal resistance insertion depth can be 1m.
When the insertion depth of the measurement original exceeds 1m, it should be installed as vertically as possible, or a support frame and a protective sleeve should be installed.