The Barber-Colman TC4112 Temperature Controller is a remote-bulb, SPDT thermostat designed for on-off control of media temperature in ducts, tanks, and liquid lines. It covers a setpoint range of 100 to 260°F and uses a copper capillary with a 6-foot length and a 3/8-inch by 4-inch copper bulb. The unit provides SPDT switching and is commonly configured with a factory-set differential around 3°F (adjustable within a 3–16°F range in some listings). Some retailer listings note a NEMA 1 enclosure when mounted, making it suitable for industrial environments.
