Extech Instruments CO240 User Manual

3 CO240-en-US_v1.9 10/22
Meter Description
1. Sensors
2. LCD Screen
3. HOLD / Up Arrow Button
4. MODE / Left Arrow Button
5. SET Button
6. AC Adaptor jack
7. Tripod Mount
8. POWER ( ) Button
9. (Max/Min) / Right Arrow Button
10. UNIT Button
11. Down Arrow Button
12. USB PC interface port
Battery compartment on rear of meter.
Operation
Powering the meter
Momentarily press the POWER button to power on the meter. Hold the POWER button for 2
seconds to turn off the meter. During measurement, if the alarm is sounding (audible beeper)
press the POWER button momentarily to turn off the beeper. Press again to activate the beeper
function. The alarm beeper is set to ON by default. The meter can be powered by 6 AAA
batteries or AC Adaptor.
Recommendation: For datalogging, power the unit using an AC/DC adaptor in order to conserve
battery power.

Extech Instruments CO240 Specifications

Display and Measurement

display	Dual multifunction LCD
CO2 measure range	0 to 9, 999 ppm
CO2 accuracy	± (75 ppm + 5% of reading) 0 to 2, 000 ppm

Operating Environment

operating temperature	0 to 50°C (32 to 122°F); 0.1° resolution
operating relative humidity	0 to 95% RH (avoid condensation)
relative humidity accuracy	± 5% of rdg at 25°C (77°F) otherwise ±7% RH

Temperature Ranges

dew point temperature range	‐72.9 to 47°C (‐99.22 to 118°F); 0.1° resolution
wet bulb temperature range	‐11 to 48.2°C (12.2 to 118.8°F); 0.1° resolution
temperature accuracy	± 1°C (1.8 °F)

Storage Conditions

storage temperature	‐20 to 50°C (‐4 to 122°F)
storage humidity	0 to 95% RH (avoid condensation)
dimensions	211 x 60 x 40 mm (8.3 x 2.4 x 1.6")

Power and Weight

power	AAA batteries x 6 pcs or AC adaptor
weight	181.4 g (6.4 oz.)