Dwyer Instruments Magnehelic 2000-0-AF Installation And Operating Instructions

The Magnehelic ® gage consists of two pressure-tight compartments separated by
a molded flexible diaphragm.
The interior of the gage case serves as the "high" pressure compartment and a
sealed chamber behind the diaphragm serves as the "low" pressure compartment.
Differences in pressure between the "high" and "low" sides of the diaphragm cause
the diaphragm to assume a balanced position between the two pressures. The
front support plate of the diaphragm is linked to a leaf spring which is anchored at
one end. The spring provides calibrated resistance to the diaphragm motion.
Motion of the spring is transmitted through an exclusive magnetic linkage to the
pointer.
The Magnehelic ® gage requires no maintenance. The only field adjustment
required is occasional zero setting of the pointer which is done by opening the
plastic vent valves and turning the adjustment of the gage.
STANDARD ACCESSORIES FURNISHED
Two 1/8˝ NPT plugs for duplicate pressure taps, two 1/8˝ pipe thread to rubber
tubing adapter and three flush mounting adapters with screws. (Mounting and snap
ring retainer substituted for 3 adapters in MP & HP gage accessories.)
Air Filter accessories furnished are mounting
panel with necessary screws, two static
pressure tips with integral compression
fittings, two five foot lengths of 1/4˝ aluminum
tubing and the two molded plastic vent valve
with compression fittings.
The Magnehelic ® gage with molded plastic vent valves for easy zeroing. Available
with adjustable signal flag (not shown; option "ASF" at extra cost) for immediate
visual reference to maximum allowable pressure drop; External front screw for zero
adjustment. Red and green scale overlays to highlight safe and dangerous
readings are also available.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A.
Series 2000 Magnehelic
Specifications - Installation and Operating Instructions
11/16
[17.46]

FEATURES

• Easiest reading for personnel accustomed to dial type gages.
• Lowest cost pointer type gage.
• Easy zeroing with molded plastic vent valves.
• Sensitivity to 0.01˝ w.c.
• Withstands vibration.
• Unaffected by over range pressure surges.

SPECIFICATIONS

Service: Air and non-combustible, compatible gases. (Natural Gas option
available.)
Wetted Materials: Consult Factory.
Housing: Die cast aluminum case and bezel, with acrylic cover, Exterior finish is
coated gray to withstand 168 hour salt spray corrosion test.
Accuracy: ±2% of full scale (±3% on - 0 and ±4% on - 00 ranges), throughout
range at 70°F (21.1°C).
Pressure Limits: -20˝ Hg. to 15 psig.† (-0.677 bar to 1.034 bar); MP option; 35
psig (2.41 bar), HP option; 80 psig (5.52 bar).
Overpressure: Relief plug opens at approximately 25 psig (1.72 kPa), standard
gages only.
Temperature Limits: 20 to 140°F.* (-6.67 to 60°C).
Size: 4˝ (101.6 mm) Diameter dial face.
Mounting Orientation: Diaphragm in vertical position. Consult factory for other
position orientations.
Process Connections: 1/8˝ female NPT duplicate high and low pressure taps -
one pair side and one pair back.
Weight: 1 lb 2 oz (510 g), MP & HP 2 lb 2 oz (963 g).
* Low temperature models available as special option.
† For applications with high cycle rate within gage total pressure rating, next higher
rating is recommended. See Medium and High pressure options at lower left.

OPERATING RANGES AVAILABLE

Model
Number
2000-0-AF
2001-AF
2002-AF
2003-AF
2004-AF
Phone: 219/879-8000
Fax: 219/872-9057
® Air Filter Gages
Ø4-1/8 [104.78] BOLT
CIRCLE FOR PANEL MOUNTING
120 APART
1/2
[12.70]
1/8 NPT HIGH
PRESSURE
1/8 NPT HIGH
PRESSURE
1/8 NPT LOW
1-1/4
PRESSURE
1-3/4
[31.75]
[44.45]
1/8 LOW
PRESSURE
7/16
[11.11]
1-11/16
1/2
[42.86] [12.70]
Minor
Range Divisions
0-.5˝ water 0.01˝
0-1˝ water 0.02˝
0-2˝ water 0.05˝
0-3˝ water 0.10˝
0-4˝ water 0.10˝
Cutaway view of the Magnehelic
the actuating diaphragm, the leaf spring with
magnet, the helix which turns the indicating pointer
in response to the position of the magnet without
mechanical linkages.
www.dwyer-inst.com
e-mail: info@dwyer-inst.com
Bulletin A-28
Ø4-3/4
[120.65]
® gage showing