Micro differential pressure gauge used to measure fan and blower pressure, filter resistance, wind speed, furnace pressure, orifice plate differential pressure, bubbles water level and liquid amplifier or hydraulic system pressure. It using frictionless magnetic components, can rapidly measure the micro-pressure air or non-corrosive gases, including positive, negative (vacuum) or differential. No wear, hysteresis and clearance. Not filling, vaporization and freezing. This design has anti-vibration, anti-shake and high overpressure capability, you can guarantee access to high precision. The design impact, shock and overload protection.