The working principle of thermocouple temperature sensor _ instrument

If two different components of homogeneous conductor loop formation, direct measure WenDuan call side, the measurement is called reference end terminal end, when there is temperature difference on both ends, will generate an electric current in the circuit, then will exist between both ends of seebeck thermoelectric potential, namely the seebeck effect. Only with the size of the thermoelectric potential thermocouple temperature difference on both ends of the conductor material and, has nothing to do with the thermocouple length, diameter of the conductor. Thermocouple has simple structure, wide applicable temperature range, easy to use, bear heat, mechanical shock ability and fast response characteristics, commonly used in high temperature area, vibration impact big bad environment and suitable for small structure such as temperature measurement occasions; But its signal output sensitivity is low, vulnerable to environmental disturbance signal and preamplifier the influence of temperature drift, therefore not suitable for measuring the temperature of the small change. Thermocouple performance and parameters of the thermocouple thermal response time step change in temperature, thermocouple output value changes to the step change of 50% of the time required to called thermal response time, with the tau zero. 5 said. Thermocouple nominal pressure generally refers to the working temperature protection tube can withstand static external pressure and not broken, in fact, the nominal pressure is not only related to protecting tube material, diameter, wall thickness, and structural forms, installation methods, in depth, and the measured medium velocity and types and so on. Thermocouple protection tube into smaller depth should not be less than the outer diameter of 8 ~ 10 times ( Special product exception) Thermocouple protection tube pipe protection is to protect the temperature sensing element, and direct contact with the measured medium, not make them avoid or reduce harmful medium erosion, flame and air flow scouring and radiation, and mechanical damage, and also plays a fixed and support the role of thermal sensor element. 321304 and 316 ( 316 l) Series stainless steel protecting tube is made of a wide range of materials, usually use under 900 ℃, the partial products can also be used to 1150 ℃; Above 900 ℃ in general use nonmetallic material protection tube. The classification of thermocouple structure according to the structure of thermocouple is divided into thermocouple temperature measuring wire, thermocouple, prefabricated thermocouple. Thermocouple temperature measuring wire with take-away insulation thermocouple wire welded together, is a kind of temperature measurement in the product structure is simple, fast response speed. The structure principle of thermocouple is made up of thermocouple wire, high purity magnesium oxide and by repeated composite stainless steel protecting tube body control and become, can bend, high pressure resistance, heat resistance to vibration, fast response time and strong and durable and many other advantages, can be directly measured in the production of a variety of 0 ~ 800 ℃ range of liquid and gas medium, as well as the temperature of the solid surface. If no special instructions, I supply standard products of the company products are less than 8 mm in diameter thermocouple thermocouple three measurement structure comparison of structure form Lou Lou in the outside end thermocouple measurement end, temperature measurement, the fastest response time is only used in the drying of corrosive medium, cannot be used in a humid air or liquid hull thermocouple heat with metal casing pipe welding electrode, the reaction time between open end type and insulation type, suitable for special occasions requiring small outside interference insulated thermocouple is used to measure the end closed internally, thermocouple and insulation between casing, not easily affected by external interference, is a common structure form of prefabricated thermocouple fabricated thermocouple is mainly composed of junction box, protection tube, thermal insulation casing, terminal blocks, electrode structure, and a variety of installation of fixture. Commonly used thermocouple compensation wire specifications according to the compensation conductor should be applicable temperature range, my company's products are mainly used two kinds of compensation standard supply wire, PVC wire and metal mesh wire compensation, compensation of PVC wire line core for type, texture soft, heat-resistant up to 80 ℃. Metal mesh compensation conductor wire core for single strands, anti-interference performance is good, heat resistance up to 400 ℃. Temperature sensor selection, determine the type of thermocouple temperature sensor, the actual use temperature range, accuracy, size and installation fixed way, etc. , according to the demand for reference later in detail selection of material, also can be customized according to customer's drawings or samples processing products for thermocouple is introduced in detail. Tel: 023 - 68280988, 023 - 68288698