TFA TA100 Mode D'emploi page 5

TFA No. 30.5010 Anleit_11/09
KLIMA GUARD
– Digital Thermo-Hygrometer
Features:
• Room temperature
• Indoor relative air humidity
• Maximum and minimum values
• Dew point
• Wet bulb temperature
• Acoustic and optical alarm function for all parameters
Due to its high precision the electronic KLIMA GUARD Thermo-Hygrometer
is an ideal measuring instrument for checking room, storage and test
bench conditions (according to ISO 9001).
The interaction of temperature and air humidity
Cold air however, can absorb only little moisture. Warm air can absorb
much more water vapour.
Dew-point:
This interdependency of temperature and relative humidity is expressed
by means of the dew-point:
If the air is cooled continuously at constant absolute humidity, then the
relative humidity will steadily increase up to a maximum of 100%. If the
air is cooled further, then the excess water vapour is separated out in
the form of water droplets.
If the measuring unit indicates an air temperature of 20° C and a relative
humidity of 65%, then the dew-point temperature will be 13.2° C. What
does that mean? That the air, for instance in your bedroom, will condense
and form water droplets at all points on walls and ceilings that are cooler
than 13.2° C, and that this may later lead to patches of mould or damp.
If the air is at a relative humidity of say 40%, then the dew-point tempera-
ture is only 6 °C. The walls and ceilings would therefore have to be signifi-
cantly colder for the air to reach its dew-point and for water droplets to
form.
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17.11.2009 15:04 Uhr Seite 5
KLIMA GUARD
– Digital Thermo-Hygrometer
Wet bulb temperature:
The wet-bulb temperature is based on the psychrometric measurement.
Water evaporating from the moistened wick on the wet-bulb thermo-
meter bulb cools the thermometer bulb and lowers the temperature
reading. The cooling effect of the evaporation from the bulb depends
on the amount of water vapor present in the air.
Operation:
Startup:
Open the battery compartment and insert 2 batteries 1.5 V AAA. Pull off
the protection foil on the display. The unit is now ready to use.
Display:
The upper row shows the indoor relative humidity, the lower row the
room temperature. The temperature unit can be changed from °C to °F
by the SET-button.
MAX / MIN temperatures:
• Press the MAX/MIN button and the highest temperature and humidity
is displayed since the last reset.
• Press the MAX/MIN button again, the display shows the lowest tempe-
rature and humidity since the last reset.
• Press the CLEAR button while the maximum and minimum temperatu-
re is displayed to reset the values to the present temperature.
Dew Point and Wet bulb temperature:
Press the ▲ button to read the Dew Point (display Td) and the ▼ button
to read the Wet Bulb Temperature (display Tw).
Auto Shut Down:
Press and hold CLEAR button. AUTO OFF appears on the display. The dis-
play will shut down if no keys are pressed for 12 minutes. In the shut
down mode, no measurement is done to save battery power. To turn on
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