PT100 Sensor - Udaipur

The illustration of the assembly is identical for both Pt100 and thermocouple sensor. The protection tube or sheath, houses the thermocouple or Pt100 either directly or indirect via an insert. Additionally a thermo well may be utilized for purposes of installing the probe into the process or application.
Sensor inserts are fabricated unit which is comprised by a sensor and a terminal base; the sensor is housed in a stainless steel insert tube, usually of 6 or 8mm diameter and, then it is inserted into the actual protection tube. Good sheathing with physical contact between the insert tip and sheath end is essential to ensure good heat transfer. Spring contact is used in the terminal base to maintain this contact. This arrangement facilitates easy replacement of the sensor whenever required. In the case of a mineral insulated thermocouple or Pt100, the sensor is designed as an integral part with the insert tube.
When a sensor insert is not specified, the sensor is housed directly in the probe and a suitable insulant is used to achieve electrical and/or thermal isolation from the sheath wall as required. The disadvantage is that whenever replacement is required than there is no alternative except, changing the entire assembly. A temperature transmitter can be fitted to the terminal base to provide a complete sensor and signal-conditioning insert.
A thermowells or pocket can be used so that there is no disturbance to the process when sensor is under replacement. Thermowells also provide protection to the sensor against aggressive media as well as it maintains physical process integrity in the event of sensor removal if it is fitted permanently into the process via a thread or flange.
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