• Simultaneously displays carbon monoxide (CO) level and air temperature readings on large LCD display
  • Ranges:
    • Carbon monoxide: 0 to 999 ppm, ±5% of reading or ±10 ppm accuracy
    • Temperature: 14 to 122˚F, ±1.2˚F accuracy
  • Designed with vented ball (electrochemical CO sensor) for sensing CO gas quickly
  • High alarm set point
  • Visual and audible beeper alarm default at 30 ppm (adjustable from 0 to 999 ppm)
  • Manual calibration in fresh air
  • Stores Max readings of CO and Temperature
  • Max Hold and Data Hold during use
  • Auto Power off with disable
  • Low battery indicator
  • Tripod mount (tripod sold separately)

What's in the Box

  • Soft case
  • 4 AAA batteries

The Extech CO40 Carbon Monoxide Meter is a handheld instrument that simultaneously measures in addition to carbon monoxide. The fully calibrated instrument will provide years of reliable service in a number of applications including: HVAC service on furnaces and hot water heaters, home inspections, blocked chimneys, out-of-adjustment burners, gas-powered generators, ambient air safety checks on residential appliances, and industrial environments where the accumulation of CO is possible.

The Extech CO40 uses vented ball technology to provide fast response (under 30 seconds) for sensing CO gas across the range of 0 to 999 ppm. The CO40 stores maximum readings of both CO levels and temperature and includes max hold and data hold during use. The user‐programmable visual and audible alarm alerts the user if the CO level rises above the programmed limit. The CO40 also includes a tripod mount.