The Series 475 Mk III Handheld Digital Manometers from Dwyer Instruments, Inc. now includes a versatile new pressure unit selection key for instant switching between inches water column / kilopascals or psid / bar. This new feature eliminates tedious and time consuming calculations and the potential for errors. They are ideal for plant engineers, industrial hygienists and service technicians for monitoring clean rooms; HVAC and other pneumatic systems. These compact instruments measure positive, negative or differential pressures of air and other compatible gases to within 0.5% full scale accuracy. Built-in compensation limits the effects of temperature to +/-0.5% over a range of 32-122°F (0-50°C). Rugged extruded Aluminum housing with water resistant front panel provides excellent protection for the solid state circuitry and silicon piezoresistive sensor. 
Readout is 1/2" high liquid crystal with plus or minus indication and "low battery" warning. Dual size barbed connection adapt to 1/8" or 3/16" I.D. rubber or vinyl tubing; High pressure models feature compression fittings for 3/16" hose.