Swichgage instruments are high-quality diaphragm-actuated, dial gauges for various with built-in electrical switches. Used for tripping alarms and/or shutdown devices, the pointer acts as both an indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contacts have a self-cleaning motion to ensure electrical continuity. More compact, gauge-only models without contacts (known as Murphygage instruments) are also available.
The 20DP and A20DP Series (2 inch/51 mm dial) and the 25DP and A25DP Series (2-1/2 inch/64 mm dial) Swichgage instruments are diaphragm-actuated, differential pressure-indicating