CO250 Datasheet, PDF (4/10 Pages) Extech Instruments Corporation. – CO2 Meter

Operation
BATTERY INSTALLATION
The meter is powered by 4 AA batteries or a DC adaptor. Install the batteries into the rear
battery compartment observing correct polarity. When an adaptor is used, the batteries will
be disconnected from the meter. The adaptor cannot be used as a battery charger. When
the battery voltage drops below the required level, and “Lob” will appear on the
display, a beeper sounds and readings are no longer displayed. (Press any key but the
SET to stop the beeps). Replace the batteries to resume normal operation.
CO2
O
%
POWER ON/OFF
Press SET to turn the meter on and off. At power up, the meter emits a short beep and
performs a 30 second countdown for meter warm up. It then enters the normal operation
mode with current CO2, temperature and humidity readings displayed.
CO2
O
%
TAKING MEASUREMENT
The meter starts measurements when powered on and updates readings every second. If
the operating environment changes (ex. from high to low temp.), it takes 30 seconds for
CO2 sensor to respond and 30 minutes for RH.
NOTE: Do not hold the meter close to your mouth or any other source of CO2.
AIR, DP and WBT Measurements
Press the DP/WBT button to switch temperatures display. The lower left display will cycle
from “AIR” air temperature, “DP” dew point temperature and “WBT” wet bulb temperature.
DATA HOLD
Press the HOLD button to freeze the readings, The "HOLD” icon is displayed on the left
top of the display. All current readings are held unchanged, except STEL and TWA. Press
“HOLD” again to cancel the hold function.
BACKLIGHT
Press the MODE/▲
function.
button for more than 1 second to activate or to cancel backlight
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CO250 V1.2 1/09