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5.22 Explanation of the measured values
Depending on the measuring mode and used probe, the following measured values can be
selected to be displayed in the corresponding measurement units:
[unit]
measured value
meaning
[g/m
3
]
Absolute
humidity
Indicates the mass of water vapour in relation to the volume, in which
the humid gas is contained, in:
• grams per cubic metre
• grains per cubic foot
[gr/ft
3
]
[hPa]
Absolute
pressure
Indicates the barometric air pressure. This is the currently present pres-
sure, based on an absolute vacuum of "0" and thus termed absolute
pressure. Possible units are:
• hectopascal
• millimetres of mercury
• pounds per square inch
[mmHg]
[psi]
[°C]
Ice bulb
temperature
Indicates the temperature setting in at the interface of an icy surface
and a gas gushing past in:
• degrees Celsius
• degrees Fahrenheit
[°F]
[°C]
Wet bulb
temperature
Indicates the temperature setting in at the interface of a wet surface and
a gas gushing past in:
• degrees Celsius
• degrees Fahrenheit
[°F]
[°C]
Frostpoint
temperature
Indicates the temperature setting in dur- ing icing when the current parti-
al water vapour pressure equals the saturated vapour pressure in:
• degrees Celsius
• degrees Fahrenheit
[°F]
[kg/m
3
]
Air density
Indicates the mass of air in proportion to a certain volume in:
• kilograms per cubic metre
• pounds per cubic foot
[lb/ft
3
]
[g/kg]
Saturation
ratio
Indicates the relative mass ratio of ambient air saturated with humidity
in the total mass in:
• grams per kilogram
• grains per pound
• parts per million
[gr/lb]
[ppm]
[g/kg]
Mixing ratio
Indicates the mass of water vapour in proportion to the mass of dry gas
in:
• grams per kilogram
• grains per pound
• parts per million
[gr/lb]
[ppm]
[g/kg]
Mass fraction
water vapour
Indicates the mass of water vapour in proportion to the mass of humid
gas in:
• grams per kilogram
• grains per pound
• parts per million
[gr/lb]
[ppm]
[ft
3
/h]
Norm volumetric
flow
Converts the measured volumetric flow employing the ideal gas law to
standard conditions (temperature and pressure). The following standard
conditions can be set:
• DIN 1343: 0 °C/1013,25 mbar
• DIN ISO 2533: 25 °C/1013,25 mbar
• DIN 1945-1: 20 °C/1013,25 mbar
The following units can be selected:
• cubic feet per hour
• cubic feet per minute
• cubic feet per second
• cubic inches per hour
• cubic inches per minute
• cubic inches per second
• litres per minute
• cubic metres per hour
• cubic metres per minute
• cubic metres per second
[ft
3
/min]
[ft
3
/s]
[in
3
/h]
[in
3
/min]
[in
3
/s]
[l/min]
[m
3
/h]
[m
3
/min]
[m
3
/s]
[hPa]
Partial vapour
pressure
Indicates the partial pressure of water in its gaseous phase in a given
volume of a gas or gas mixture in:
• hectopascal
• pounds per square inch
[psi]
[%]
Relative humidity
Indicates the relative humidity as the ratio of the partial water vapour
pressure to the saturated vapour pressure under saturation conditions
above water in per cent.