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MEASURING ENTHALPY
Enthalpy is a measure of the amount of energy needed to change
the state of a substance from a solid to a liquid or from a liquid to
a gas. The most common application for the DAF3009's enthalpy-
calculating algorithm is measuring the enthalpy of vaporization of
air in an HVAC/R system duct.
To enter Enthalpy mode, press the SET button with RH flashing on
the top line of the LCD. This will change the flashing term to BTU.
To stop BTU from flashing, press the MODE button.
You can now enter your preference for using the metric or Imperial
unit for Enthalpy—kiloJoules per kilogram (KJ/kg) or British
thermal units per pound (BTU/lb), respectively. To change KJ/kg
to BTU/lb, begin by pressing the UNIT button. This will cause
KJ/kg to begin flashing. Then press the SET button, followed by
the UNIT button to save the selection.
Selecting the Enthalpy unit will cause the default temperature unit
at the right of the lower readout to begin flashing. To change the
unit, press the SET button, followed by the UNIT button to save
the selection. To leave the unit unchanged, press the UNIT button.
To make an Enthalpy measurement, remove the vane and
sensor protection cap and enter Enthalpy mode (with BTU
appearing on the top line of the LCD). Turn the vane at the top of
the unit perpendicular to the source of air or wind. It makes no
difference whether the front of back of the vane faces the flow.
The measured Enthalpy value will appear on the upper readout.
Allow a few seconds for the reading to stabilize.
SPECIFICATIONS
Air Speed Measurement Range:
80 to 5910 ft./min (0.4 to 30 m/s)
Air Speed Measurement Accuracy:
12
±(3% of full-scale value + 40 ft./min (0.2 m/s))
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