The Magnahelical Gauge is the industry standard for measuring fan and blower pressures, filter resistance, air velocity, furnace draft, pressure drop across orifice plates, liquid levels with bubbler systems, and pressures in fluid booster or fluidic systems. Gauge motion is damped with high viscosity silicone fluid. Zero adjustment screw is conveniently located in the plastic cover, and is accessible without removing the cover. O-ring seal provides tightness. Rugged design resists shock, vibration, and overpressure. Propeller is precision machined from a high magnetic permeability alloy. Mounted in jeweled bearings, it rotates freely, following the magnetic field to move the pointer across the scale. Samarium cobalt magnet is mounted on one end of the range spring and rotates the propeller without mechanical linkages.