Do you know how does K thermocouple conductors are made?

The principle of thermocoupleis based onthe binding ability of metal atoms(ions) to free electrons in metals related to temperature, different kinds of metal atoms(ions) have different binding abilities to free electrons. The metal on both sides of the fusion interface after two kinds of metals are welded together has different binding ability to free electrons, the large one is positively charged and the other side is negatively charged. There is electromotive force (EMF) difference between the two sides of metals that be changed with the temperature, the value of EMF is small but can be accurately measured.

Thermocouple’s features are widely temperature range, stable performance, simple structure, fast response and the ability to remotely transmit 4-20mA signals for automatic control and centralized control.

The positive of type K thermocouple conductor is mainly made of nickel chromium alloys, the negative of type K thermocouple conductor is mainly made of nickel silicon alloys, its manufactured processes as follow: thermocouple metal alloys smelting process; thermocouple wire element drawing process; bare thermocouple wire welding and product testing.

a, The various elemental materials are added together to the melting equipment in proportion to the thermocouple alloys ingot under the negative pressure state, and it is subjected to elemental analysis. To ensure the precision of the composition analysis, the Fe content is required to be analyzed that need to be controlled within the range of 0.05±0.02%. The vacuum degree is controlled to 10-2 level, which reduces the oxygen content and improves the purity of thermocouple alloy.

b,The thermocouple alloys firstly are subjected to hot-rolling into 8mm bar for the drawing process, remove 0.5kgs at the both ends. The pass rate of the wires should be controlled at 60%, the drawing lubricant applications having reducing properties can ensure there is no serious oxidation during annealing.

c,The production of type K thermocouple alloys is divided into the production of nick chromium alloy wire and nickel silicon alloy wire, the two kinds of wires are welded together forming the closed loop.