Vaisala GMW90 - Manual (Page 16)

User's Guide _______________________________________________________________________
14 ___________________________________________________________________ M211659EN-B
Output Parameters Explained
Table 5 Parameters Supported by GMW90 Series
Parameter Symbol Unit(s) Description
Carbon
dioxide
CO2 ppm Concentration of carbon dioxide
gas (CO
2
).
Temperature T °C
°F
Temperature in Celsius or
Fahrenheit scale.
Relative
humidity
RH % Ratio of the partial pressure of
water vapor in the air to the
saturation vapor pressure of air
at the current temperature.
Dewpoint Td °C
°F
Temperature at which the water
vapor in the air will condense into
water at the current pressure.
Dewpoint Tdf °C
°F
Same as Td, except when the
dewpoint is below 0 °C, the
transmitter outputs frostpoint (Tf)
instead of dewpoint.
Dewpoint
depression
dTd °C
°F
Difference between ambient
temperature and dewpoint (Tdf).
Wet bulb
temperature
Tw °C
°F
The minimum temperature that
can be reached by evaporative
cooling in the current conditions.
Absolute
humidity
a g/m3
gr/ft3
Quantity of water in a cubic meter
(or cubic foot) of air.
Mixing ratio x g/kg
gr/lb
Ratio of water vapor mass per
kilogram (or pound) of dry air.
Enthalpy h kJ/kg
btu/lb
Sum of the internal energy of a
thermodynamic system.
NOTE All of these parameters are visible and selectable using the service port
(serial line and MI70 indicator use) even if your transmitter model does
not have a humidity sensor. However, the transmitter will not show any
measurement results for parameters that it cannot measure or calculate.