Overview
The Dwyer 2002C AV Magnehelic gauge is a precision differential pressure measurement instrument from Dwyer Instruments’ Series 2000 line. It features a dual-scale dial displaying both inches of water column (0-2.0″ w.c.) and air velocity (1000-5600 FPM), making it ideal for HVAC applications, fan and blower monitoring, and filter resistance measurement. Using Dwyer’s simple, frictionless Magnehelic gauge movement, it quickly indicates low air or non-corrosive gas pressures—either positive, negative (vacuum) or differential.
Key Features
- Accuracy within 2% across the measurement range
- Die cast aluminum case with acrylic cover; exterior finish is coated gray to withstand 168 hour salt spray corrosion test
- Dual-scale dial for convenience: 0-2.0″ w.c. and velocity in FPM
- Frictionless movement indicates low pressures and resists shock, vibration and over-pressures
- Motion is damped with high-viscosity silicone fluid; zero adjustment screw conveniently located in plastic cover and accessible without removing cover
- Industry-standard for fan/blower pressures, filter resistance, and air velocity measurement
Technical Specifications
| Measurement Range | 0-2.0″ w.c. (water column) / 1000-5600 FPM (air velocity) |
| Accuracy | ±2% of full scale at 70°F |
| Pressure Limits | -20 in Hg to 15 psig (-0.677 to 1.034 bar) |
| Temperature Operating Range | 20 to 140°F (-6.67 to 60°C) |
| Connection Type | 1/8″ NPT (female) duplicate high and low pressure taps—one pair side, one pair back |
| Case Material | Die cast aluminum with baked gray hammerloid finish |
| Cover Material | Clear acrylic, highly resistant to breakage |
| Mounting Style | Surface or flush panel mounting (bezel flange provided) |
| IP Rating | IP67 (weatherproof) |
| Gauge Type | Differential, positive, negative (vacuum), or compound |
| Series | Series 2000 Magnehelic |
| Relief Plug Setting | Opens at approximately 25 psig (1.72 bar) |
Typical Applications
The Magnehelic gauge is the industry standard to measure fan and blower pressures, filter resistance, air velocity, furnace draft, pressure drop across orifice plates, liquid levels with bubbler systems, and pressures in fluid amplifier or fluidic systems. The dual-scale design is particularly useful for:
- HVAC system air velocity and static pressure monitoring
- Filter status and pressure drop measurement
- Clean room and negative pressure room pressure control
- Blower and fan performance verification
- Orifice plate pressure drop calculation
- Ductwork and ventilation system balance
Compatibility & Replacements
Compatible With
- 1/8″ NPT process connections (standard industrial fittings)
- Clean dry air, inert gases, nitrogen, helium applications
- Non-corrosive dry gas environments
- Surface-mounted or flush panel installations
- Dwyer accessory kits (A-610 mounting, A-432 portability, A-605 air filter)
Replaces / Drop-In Replacement For
The Dwyer 2002C AV is part of the Series 2000 Magnehelic family. Verify compatibility with your system integrator before ordering, as pressure range options (standard, medium pressure, high pressure) vary by model suffix.
Works With
- Standard 1/8″ NPT tubing adapters (included)
- Rubber tubing for flexible pressure connections
- Flush mounting panel hardware (included)
- Manual HVAC and mechanical systems (no electrical connection required)
