Magnehelic Pressure Guage 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,-100 Pa, -125 Pa, 10MM and [...]