Retrotech DM-2A 用户手册

Retrotec Energy Innovations, Ltd.

DM-2A Mark II   2008-02-22

•  Flow Pressure  The pressure difference between inside the fan (in the flow stream) 

and ambient air, outside the fan.

•  Room Pressure  The pressure difference between inside the building/room under 

test and the ambient outside air.

•  Pascal (Pa)  Often abbreviated to Pa, this represents a very small metric unit of 

pressure. There are 249 Pascals in 1 water column. A water column is the pressure 
required to push water up 1 inch in a tube. One Pascal = 0.000145 pounds per square 
inch.

•  /h  Per hour
•  cfm  Cubic feet per minute
•  cm

  Square centimeters

•  fpm  Feet per minute
•  fps  Feet per second
•  ft

  Square feet

•  in wc  Inches of water column
•  in

  Square inches

•  km/h  Kilometers per hour
•  l/s  Liters per second
•  m/s  Meters per second
•  m

  Square meters

•  m

/h  Cubic meters per hour

•  m

/s  Cubic meters per second

•  mph  Miles per hour
•  Pa  Pascals
•  PSF  Pounds per square foot
•  Sig Fig  Significant figures
•  l/s/m

  Liters per second per square meter

•  NLA  Normalized leakage area

DM-2A Mark II Dual-Channel Pressure Gauge