First state whether the reading is at a pipe surface or through a process connection. For a vessel, tank or pipeline point, include the medium, mounting space, connection, operating conditions, response requirement and receiving instrument.
You can review the Thermocouple With Threaded Fixed Plug and RTD With Weatherproof Head product details. Their titles alone do not establish suitability for your process point; compare the documented specifications with the medium, temperature, pressure and installation.
For a replacement, attach the existing sensor description or drawing. If you are describing several points, list each separately with its mounting, cable route, signal input and maintenance access. This gives the enquiry a clear starting point without assuming one sensor construction suits every point.