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Professional Units Only
Kestrel Professional Meters can calculate air flow
through a duct by combining user input information
about the size and shape of the duct with the
measured air velocity. In addition to reading the
instantaneous Air Flow off the main measurement
screen, a more accurate result may be obtained
by capturing an average air flow on the Min/Ave/
Max screen while traversing the duct. Capturing an
average can be particularly helpful when measuring
ducts with registers or dimensionally uneven air flow.
» From any current measurement screen, scroll to
AIR FLOW and select Settings.
» Set Shape to match the shape of the duct, either
Rect (rectangle) or Circle.
» Input the dimensions of the duct by setting
Length and Width for a Rectangle or Diameter
for a Circle duct and press exit.
MEASURING AIR FLOW
Professional Units Only
Kestrel Professional Meters can calculate a concrete
evaporation rate (ACI 308) by combining a user input
concrete temperature with measured air temperature,
wind speed and relative humidity. Concrete mix
temperature is generally measured with a probe or
infrared thermometer and should be read at the time of
making the evaporation rate measurement.
MEASURING EVAPORATION RATE:
» From any current measurement screen, scroll to EVAP
and select Settings.
» Measure the temperature of the concrete mix and set
Mix Temp to the correct value, then press exit.
» To take a reading, hold the unit vertically,
approximately 20 inches above the surface of the
concrete while facing the rear of the unit directly
into the wind. To avoid inaccurate Evaporation Rate
readings due to thermal loading it is best to shade
the Kestrel. (Be sure the source of shade is not
obstructing the wind speed measurement.)
» The ACI recommends taking a 6-10 second average of
the evaporation rate to account for fluctuating wind
speeds. To measure an average Evaporation Rate,
scroll right from the Current Measurement Screen to
the Min/Ave/Max Screen and press select to manually
start and stop a capture.
MEASURING EVAPORATION RATE
