Barton Instruments Model 322C Blind Switch

Barton Instruments Model 322C Blind Switch

The barton Instruments Model 322C is a blind SPDT, snap-acting switch designed for use in hazardous areas. An optional two-switch configuration is available. The Model 322C provides a highly repeatable alarm signal capable of performing electrically controlled system functions for liquid level and flow applications.


The switch is adjustable to open (normally closed) or close (normally open) on either increasing or decreasing DP and is positively locked to prevent drift. Switch adjustments are
accessible when the cover is removed.

• AC Rating:
• 5 amps @125V
• 2.5 amps @240V

• DC Rating:
• (Inductive) 2.5 amps @30V
• (Resistive) 4.0 amps @30V
• Actuated by the 224 DPU


For flow applications, the unit is connected by tubing to the LP and HP sides of the primary device (orifice plate, venturi, or flow tube) in the process run. For liquid level, the DPU is connected to measure the variations in DP produced when the liquid level varies. These changes are used to control the switch function.

The electrical alarm or control unit circuit is connected to the switch (mounted on the DPU). Movement of the DPU shaft actuates the switch mechanism when the DP reaches a pre-set level.


Barton Instruments Model 322C Blind Switch