The Murphy 300-440F Mechanical Temperature Swichgage with 12 Ft Capillary A20T-440-12-1/2 is a diaphragm-actuated, temperature-indicating gage with built-in electrical switch for tripping alarms and/or shutdown devices. This rugged, built-to-last instrument is fully sealed from the environment by the unique combination of a polycarbonate case and lens, a polished stainless steel bezel, and O-ring seals. This vapor actuated gauge features a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure against a diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gage reading.
The gage pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contact(s) are isolated from ground. They have self-cleaning motion to enhance electrical continuity. Applications for A20 series temperature swichgage instruments include: engines and equipment in oil field, marine, irrigation, construction and trucking industries. Monitoring engine coolant temperature, crankcase oil and transmission oil.
- 2 inch/51 mm dial
- O-ring Seals
- Polished Stainless Steel Bezel
- Corrosion Resistant Polycarbonate Case
- Indicating Gage and Limit Switch
- Switch Can Activate Alarms and/or Shut Down Equipment
- Contact(s) Isolated From Ground
- Part No.: A20T-440-12-1/2
- Range: Range: 300 – 440°F (149 – 227°C)
- Gage Accuracy: Temperature Range 300 to 440°F (149 to 227°C); Lower 1/3 of Scale ± 9°F (± 5°C); Middle 1/3 of Scale ± 5°F (± 2.4°C); Upper 1/3 of Scale ± 4°F (± 2°C)
- Maximum Temperature: 500°F (260°C)
- Standard Settings: 400°F (204°C)
- Adapter Nut: 1/2-14 NPT
- Dial: White on black
- Case: Glass filled/Polycarbonate, corrosion-resistant; steel mounting clamp included
- Bezel: Polished stainless steel
- Pointer: Tempered nickel silver; red tip
- Lens: Polycarbonate, high-impact.
- Sensing Element: Beryllium copper diaphragm
- Sensing Bulb: Copper
- Capillary: PVC armored copper; 12 ft.
- Sensing Bulb: Copper
- Adjustable Limit Contact: SPST contact; pilot-duty only, 2 A @ 30 VAC/VDC; isolated from case ground. Normally Closed when the high limit is met. Normally Open when pointer is in normal operating range. Contacts are gold flashed silver
- Limit Contact Adjustment: by a 1/16 in. hex wrench thru 100% of the scale
- Wiring: Number 4 screw terminals
- Unit Weight: 11.9 oz. (0.370 kg)
- Unit Dimensions: 4-3/4 x 4-3/4 x 3 in. (121 x 121 x 76 mm)