The superiority of armoured thermocouple mainly in what aspects?

Armoured thermocouple can bend, high pressure resistance, heat fast response time and strong and durable many advantages, such as it and industrial prefabricated thermocouple, as measure temperature transmitter, and usually display meter, recording meter and electronic regulator, at the same time can also be as prefabricated thermocouple. It can be directly measured in the production of chian from 0 ~ 800 ℃ in the scope of liquid, steam and gas medium, as well as the temperature of the solid surface. By welding on both ends of the two different ingredients of conductor, form a loop, directly measuring WenDuan call work side, the terminal end is called the cold end, also known as the reference.

when work end and reference end there is temperature difference, will produce thermal current in the circuit, connected to display instrument, the instrument will indicate the thermocouple thermoelectric emf generated by the corresponding temperature value. The thermocouple thermoelectric emfs growth over the course of measuring the temperature, the size of the thermoelectric emfs and thermocouple temperature difference on both ends of the conductor material and, only has nothing to do with hot electrode length and diameter. The structure principle of thermocouple is, is made up of a conductor, high insulation magnesium oxide, coat 1 cr18ni9ti stainless steel protecting tube, after many integrated control. Thermocouple products are mainly composed of terminal block, terminal and armoured thermocouple basic structure, and with various mounting device.

1) Under the condition of mechanical strength to allow, as far as possible choose coefficient of thermal conductivity small diameter and thin hot electrode materials, thermal electrode diameter usually 0. 2 - 0. 5 mm.

( 2) When installation, all children don't destroy the measured surface temperature field and the geometry shape of the object to be tested.

( 3) Armoured thermocouple measuring side should be measured table and have a good thermal contact with, contact method to pick up address (state Refers to the surface under test to allow welding) 。 Solder joints are not allowed to have slag and porous sponge, solder joint is smaller, at the same time to ensure the enough strength. In order to enhance the thermocouple measuring the welding strength, can be hot electrode welding part slightly flattened.

( 4) When laying surface thermocouple, as far as possible to eliminate the influence of convection. For example in the measured surface flow gas Hugh, in situations where conditions permit, had better use the embedded thermocouple method. But will try to pay attention to the slot size is small, town should be done after embedding surface polishing, surface level, to be tested. If the surface to be measured is both gas flow, and does not allow grooving buried, after laying thermocouple, can be installed the wing shape confinement or square shield ( As shown in figure) To reduce the interference of convection.

( 5) Wear-resistant thermocouple measuring side as far as possible close to the surface to be tested. For the measurement end of the spherical measurement can be squashed. When the coefficient of thermal conductivity of the object to be tested is very small, can be used with good heat conduction performance of the collector.

( 6) Isothermal laying can effectively reduce the error of thermal conductivity. Measuring side behind the hot electrode should be measured surface along the laying length of at least 50 times hot electrode diameter. Along the table to be tested and thermoelectric extremely insulation layer should be thin and material thermal conductive performance is better, to strengthen between the thermal conductivity of thermal electrode and the surface to be tested. Electrode measured surface after derivation, hot thicker electrode insulation requirements, good insulation, electrode to reduce the heat to air cooling. If platinum-rhodium thermocouple measuring circuit resistance is too large, it can take thick hot lap electrode method, selecting two hot electrode thickness lap, attention should be paid to the thermoelectric properties consistent as far as possible.

( 7) When conditions change and as instantaneous measurements, choose a better dynamic response of the surface of the thermocouple.

( 8) Hot electrode materials should have good thermoelectric properties, stability and uniformity. Before making response to hot electrode materials to check, ensure good properties of electrode materials and reliable.