4
Operation
Power On/Off
Plug in the adaptor and the meter turns on automatically with
a short beep. It will perform a 30 seconds countdown for me-
ter warm up, then enters normal mode with current CO
2
, tem-
perature, and humidity readings displayed.
Taking a Measurement
The meter measures continuously and updates the LCD
every second. With a significant environmental change, the
CO
2
sensor requires 30 seconds, and the RH sensor 30 min-
utes to respond. Note: Do not hold the meter close to the
face because exhalation affects the CO
2
reading.
Switch Temperature Measurement
Press the Up/DP/WBT key to cycle the temperature display
between air, dew point, and wet bulb temperatures.
MIN, MAX, STEL, TWA
Press the M
N
X
/AVG/Down button to switch between the nor-
mal, minimum, maximum, and weighted average readings.
In MIN and MAX modes the minimum and maximum readings
for CO
2
, air/dew point/wet bulb temperature, and RH will dis-
play.
In STEL and TWA modes, the display shows the weighted
average of the CO
2
readings for the past 15 minutes (STEL)
or 8 hours (TWA), as well as the current readings for air/dew
point/wet bulb temperature, and RH.
Setup
In normal mode, hold down the SET button for at least 1 sec-
ond to enter setup mode. To exit setup, press the CAL/ESC
button.
P1.0 Set CO
2
Alarm
When entering setup mode, “AL” and “P1.0” are displayed on
the LCD. Press the SET button again to enter “P1.1” to set
the CO
2
alarm upper limit (exceeding this triggers the alarm).