DWYER PHOTOHELIC® A3000 SERIES | DIFFERENTIAL PRESSURE SWITCH/GAGE

A3000 Photohelic® Switch/Gages for Pressure Measurement up to 25 psig.

The Series A3000 Photohelic® operates as a dual-function instrument, providing a continuous visual indication of differential pressure while simultaneously controlling two SPDT relay contacts. The gage portion uses the time-proven, frictionless Magnehelic® movement, ensuring ±2% accuracy across the entire scale. The switching portion utilizes high-speed phototransistors and light-controlled relays to trigger setpoints with zero mechanical drag on the pointer.

Each of the two setpoints is fully adjustable via knobs on the front face, allowing for independent high and low limit control. This “deadband” or “gap” between setpoints can be adjusted from the width of the pointer up to the full scale of the instrument. The A3000 is housed in a rugged, weather-tight die-cast aluminum case, making it suitable for even the harshest industrial environments.

PRODUCT USES:

• Dust Collector Systems: Initiating cleaning cycles (pulse-jet) when filter resistance reaches a high setpoint.
• Air Filter Monitoring: Activating remote alarms when filters in HVAC or laminar flow benches are clogged.
• Cleanroom Pressurization: Maintaining constant positive or negative pressure by controlling supply/exhaust fans.
• Pneumatic Conveying: Monitoring for line blockages or blower failure.