Data Sheet for Product

TT 184 Temperature Transmitters Technical Instructions
Document Number 155-077P25
February 15, 2022
Siemens Industry, Inc. Page 3
Operation
The transmitter is provided with a restricted (40 scim) supply of air. Assume a rise in
temperature at the transmitter sensing element. The free end of the bimetal, the rod and
tube, or the liquid-filled element moves downward. This increases the load on the
throttling pin (or throttling ball) and moves it closer to the nozzle. Pressure builds up in
the chamber below the nozzle until the force of the increased air pressure against the
bottom of the throttling pin exactly balances the downward force of the free end of the
sensing element.
Figure 1. Operation of the Room Transmitter.
Figure 2. Operation of the Remote Bulb.
Figure 3. Operation of the Rigid Bulb.