Service life of S-type assembled thermocouple and armored thermocouple

The lifespan of S-type thermocouples is not only related to normal protection and maintenance, but also to the deterioration of S-type thermocouples. Rare S-type thermocouples, including S-type detachable thermocouples and S-type armored thermocouples. So what is the service life of these two S-type thermocouples?

1. Application life of S-type detachable thermocouple

Only the stability of thermocouples is required at the scale of our country. Namely, the change in thermoelectric potential before and after application at a certain temperature for 200 hours. However, there is no established definition for the lifespan of applications yet. The request for the service life of thermocouples in Japan is based on the continuous application time of thermocouples specified in the Japanese JIS (C-1602-1995) standard. For type B, R, and S thermocouples, it is 2000h, while for type K, E, J, and T thermocouples, it is 10000h.

In practical applications, S-type detachable thermocouples usually have maintenance tubes and are only used with bare wires in special circumstances. Therefore, in a few places, the lifespan of the maintenance tube determines the lifespan of the thermocouple. According to the Japanese JIS (C-1602-1995) standard, the continuous application time of S-type detachable thermocouples is 2000 hours.

2. Application life of S-type armored thermocouple

Because armored thermocouples have sleeves for maintenance and isolation from external conditions, the material of the sleeves has a significant impact on the lifespan of armored thermocouples. Therefore, it is necessary to choose thermocouple wires and metal sleeves based on their intended use. After the material is selected, its lifespan increases with the increase of the diameter of the armored thermocouple. Compared with detachable thermocouples, armored thermocouples have many advantages, but their service life is often lower than that of detachable thermocouples.