News Details

Sheathed thermocouples are flexible, high-temperature resistant, fast thermal response, and robust. Like industrial assembled thermocouples, they serve as temperature sensors and are typically used with display instruments, recording instruments, and electronic regulators. They can also be used as temperature sensing elements for assembled thermocouples. They can directly measure the temperature of liquids, steam, gas media, and solid surfaces within the range of 0℃ to 800℃ in various production processes, conforming to the GB/T18404-2001 standard.

□ Working Principle

The working principle of a sheathed thermocouple is that two conductors of different materials are welded at both ends to form a loop. The direct temperature measurement end is called the measuring end, and the wiring end is called the reference end. When there is a temperature difference between the measuring end and the reference end, a thermal current is generated in the loop. When connected to a display instrument, the instrument indicates the corresponding temperature value of the thermoelectric electromotive force generated by the thermocouple.

The thermoelectric electromotive force of a sheathed thermocouple increases with the temperature rise at the measuring end. The magnitude of the thermoelectric electromotive force depends only on the material of the sheathed thermocouple conductors and the temperature difference between the two ends, and is independent of the length and diameter of the thermoelectrodes.

The structure of a sheathed thermocouple consists of conductors, insulating magnesium oxide, and a 1Cr18Ni9Ti stainless steel protective tube, which is drawn multiple times. The sheathed thermocouple product mainly consists of a junction box, terminal block, and sheathed thermocouple as the basic structure, equipped with various installation and fixing devices.

Sheathed thermocouples are divided into insulated type and grounded type.

□ Main Technical Indicators

Temperature Measurement Range and Accuracy