Abstract: A temperature transmitter connects to a first conduit containing leads from a temperature sensor and also to second conduit which conveys the output leads of the transmitter to a remote location. A wall in the transmitter divides the transmitter into first and second compartments sealed from one another. The first compartment receives the leads from the temperature sensor and contains the electric circuit for converting the signal of the temperature sensor to an output signal representative of temperature. A feedthrough passing through the wall connects the output signal to the output leads in the second compartment. The arrangement blocks the flow of potentially hazardous fluid from the first conduit through the second conduit to a remote location such as a control room. The transmitter thus provides an integral seal between the conduits and use of an external conduit seal in the second conduit can be avoided.