Instructions

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8
2. THE USER INTERFACE
The user interface consist of a backlit LCD graphic display, and the power-on and setting keys.
When battery powered, and not pressing any key, the backlight turns off after about 1 minute. To
turn it back on, press any key. When using an external power supply, the backlight is always on.
Turn the instrument on and off with the ON/OFF key. When you turn the instrument on, the logo
and model will be displayed for a few seconds, and then the main display.
The quantities detected by the instrument can be viewed with a larger character size, at the top of
the display. The parameter displayed with a larger character is called main quantity. In order to
select the parameter to be displayed as main quantity, use the ▲▼ keys. For some quantities, you
can select the unit of measurement; temperature can be displayed as °C or °F.
2.1 THE HD21ABE DISPLAY
HD21ABE
2010/02/10 08:00:00
Carbon Dioxide
CO
2
600
ppm
CO 0 ppm
Patm 1000 hPa
1. Battery’s charge status and instrument code. In case the logging function is on, this line
shows the current logging number and the time elapsed from logging start.
2. Main quantity (in this case, CO
2
Carbon Dioxide).
3. Display of all other quantities.
4. Current date and time.
The detected quantities are:
CO
2
Carbon Dioxide
ppm
CO
Carbon Monoxide
p
p
m
Patm
Atmospheric Pressur
e
hPa
1
3
4
2