Extech Instruments CO240 User Manual

5 CO240-en-US_v1.9 10/22
CO
2
Alarm Setting
Press and hold the SET button for 2 seconds to enter the high CO
2
alarm threshold. Press the
HOLD button to increase the value, and the Down arrow button to decrease the value. Press the
MODE button to select the digit to the left and press the MAX/MIN button to select the digit to
the right. Once the desired value is set, press the SET button for 2 seconds to save the alarm
setting. The LCD will return to its normal mode of operation. The meter alarm limit default is
1000ppm (OSHA). Momentarily press the POWER button to toggle the alarm on and off.
PC Software
This meter has the capability to connect to and communicate with a PC.
Check the software download page of the website www.extech.com/software/downloads for
the latest version of the PC software and its operating system compatibility.
Download and unzip the software. Run ExtechInstaller.exe and then refer to the instructions
provided in the HELP Utility within the software program.

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.)