The A20T-250-4-1/2 Temperature Swichgage has a polycarbonate case and O-ring seals. This diaphragm-actuated, 2" temperature-indicating gauge has a built-in electrical switch for tripping alarms and/or shutdown devices. This model has a polished stainless steel bezel, a 4 foot capillary length, a temperature range from 130-250°F (54-121°C), and standard 1/2-14 NPT threading.
This vapour actuated gauge features a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapour creating pressure against the diaphragm mechanism. The diaphragm translates this vapour pressure into a mechanical gauge reading.
The gauge pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contacts are isolated through ground. This gauge has a self-cleaning motion to enhance electrical continuity.
Contact form description.