Extech CO230 Operating Manual

User Guide

Wall-Mount CO2 Monitor

Model CO230

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Introduction

Thank you for selecting the Model CO230 Carbon Dioxide Monitor. This
meter measures CO2 concentration, air temperature, dew point, wet bulb
temperature and relative humidity.
The audio-visual alarm and alarm relay output make this is an ideal
instrument for indoor air quality (IAQ) diagnostics. Carbon dioxide (CO2)

is a gaseous component of the earth’s atmosphere. The concentration of

CO2 in natural ambient air is approximately 0.04% or 400ppm.
The NDIR (non-dispersive infrared) sensor provides stable, long term
monitoring.
This meter is shipped fully tested and calibrated and, with proper use,
will provide years of reliable service. Please visit our website
(www.extech.com) to check for the latest version of this User Guide,
Product Updates, and Customer Support.

FEATURES

 LCD simultaneously displays CO

Temperature (air, dew point, or wet bulb)

 Stable NDIR sensor for CO
 Weighted averaging: TWA (8 hours) & STEL (15 minutes)
 Automatic Baseline Calibration (ABC). Can be disabled for use in

areas with continuously elevated CO2 levels (>400ppm)

 Manual CO
 Audio-visual CO

calibration

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concentration warning alarm

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 Dew Point and Wet Bulb temperature calculations

 Relay output for connecting external indicators or controllers

Level, Relative Humidity, and

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detection

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Descriptions

Meter Description

1. Temperature/RH sensor

2. Main Display

3. Alarm Relay Output

4. Aux. Displays

5. 12V AC Adaptor jack

6. Keypad

7. Alarm alert lamp

8. CO

sensor

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Note: Wall mount hole and relay
wiring screws are located on the back

Display Description

1. CO

concentration (ppm)

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2. Relative Humidity (%)

3. Air Temperature, Dew Point or

Wet Bulb Temperature (°C / °F)

Display Icons

TWA Time weighted average (8 hours)
STEL Short-term exposure limit (15-min. weighted average)
HOLD Holds reading on display
MIN/MAX Minimum/Maximum readings
DP Dew point temperature
AIR Air temperature
WBT Wet bulb temperature
% Relative Humidity measurement unit
°E (C/F) Temperature units (Celsius/Fahrenheit)

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Keypad Description

SET Meter ON/OFF power

Setup mode
Save settings

CAL/ESC CO2 calibration with ▲/DP WB

RH calibration with MXN/AVG/▼

Exit setup mode

RESET Reset the meter and clear MAX/MIN readings
Terminate Calibration

▲/DP WB Selects AIR, DP, or WBT temperature display

Selects units or increases value in calibration and setup

MXN/AVG/▼ Activates MIN, MAX, STEL, TWA functions

Select mode or decrease value in calibration and setup

Operation

POWER ON/OFF

The meter is powered by a 12VDC adaptor.
Power the unit by plugging the AC adaptor into the meter and into an
AC source. The meter will switch ON with a short beep.
The LCD will perform a 30 second countdown and then displays the
current CO2 concentration, air temperature, and relative humidity.

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