The 2220-053 Room Temperature Transmitter senses room temperature and transmits a proportional pneumatic signal to a calibrated receiver gauge and/or a receiver controller. It is designed to transmit a 3-15 psig signal over a 50?-90?F span, and is factory calibrated. This unit is a "one-pipe" force balanced transmitter which must utilize an external restrictor in the supply line. It incorporates a highly sensitive bimetal thermostatic element and a ball valve with pneumatic feedback. This ensures accuracy and stability over the entire operating range. The internal parts are corrosion resistant. Flexure hinges are used instead of pivots to reduce friction, and there is an internal non-replaceable air filter to maintain cleanliness of the operating parts. These features along with simplified design and small movements of the operating parts provide an instrument with a long maintenance free operating life.