Thermowells are tubular accessories used to safeguard temperature sensors installed in industrial operations. A thermowell contains a tube closed down at one end and installed in the process stream. A temperature sensor like a thermometer, thermocouple or RTD's is placed on view end of the pipe, which is generally in the open air beyond your process piping or vessel and any thermal insulation. Thermodynamically, the procedure fluid transfers high temperature to the thermowell wall, which transfers high temperature to the sensor. Since more mass exists with a sensor-well assemblage than with a probe straight immersed in to the process, the sensor's reaction to process |emps changes is slowed with the addition of the well. In case the sensor fails, it could be easily changed without draining the vessel or piping. Because the mass of the thermowell must be warmed to the procedure temperature, and because the wall surfaces of the thermowell carry out heat from the action, sensor reliability and responsiveness is adversely influenced by the addition of a thermowell.