I am often asked why one would use a temperature transmitter in a temperature measurement solution as opposed to a wired direct installation (temperature sensor signal is taken directly back to control room/input card)
There are many benefits to installing a transmitter instead of wiring a sensor direct, including enhanced performance and accuracy of the temperature measurement point (Temperature Transmitter signals are much less sensitive to environmental effects than a wired direct sensor signal resulting in a more stable measurement). Temperature Transmitters can also compensate and filter out environmental and installation effects that can create erroneous measurement values. Dual sensor functionality in a temperature transmitter greatly reduces the risk of losing a measurement point as it can provide a seamless switchover to redundant sensor if primary fails. Finally, since a transmitter communicates over standard copper wire rather than frequently more expensive sensor wire - installation costs are often less expensive with transmitters.
-Ryan