Dwyer 1640-0 Floating Contact Null Switch Overview
The Dwyer 1640-0 Floating Contact Null Switch is a precision differential pressure switch engineered for accurate null-point detection in HVAC, building automation, and industrial air-handling applications. Designed for use with air and non-combustible gases, this switch delivers reliable high and low actuation with a user-friendly visual setpoint adjustment for fast, accurate field configuration.
Key Features
- Pressure range: .01″ w.c. to 0.2″ w.c. — ideal for low differential pressure monitoring
- Adjustable null span: 0.01″ to 0.03″ w.c. for precise dead-band control
- High and low actuation for dual-direction switching capability
- Visual setpoint adjustment for easy, on-site calibration without additional tools
- Compatible with air and non-combustible gases
- Maximum pressure limit: 10 PSIG — protects the switch in pressurized systems
- 1/8″ Female NPT connections for straightforward installation into standard piping
Application
The 1640-0 is well-suited for critical pressure monitoring tasks where detecting a near-zero differential is essential. Typical applications include filter status monitoring, clean room pressure verification, airflow proving, and balancing of air distribution systems. Its floating contact design ensures the switch output remains stable within the null span, reducing nuisance trips caused by minor pressure fluctuations.
Specifications
- Brand: Dwyer Instruments
- Model / SKU: 1640-0
- Pressure Range: .01″ w.c. to 0.2″ w.c.
- Adjustable Null Span: 0.01″ to 0.03″ w.c.
- Actuation: High and Low
- Setpoint Adjustment: Visual
- Media: Air and Non-Combustible Gases
- Maximum Pressure Limit: 10 PSIG
- Port Connections: 1/8″ Female NPT
