Skip to content
AkerminMeasure. Monitor. Improve. Compare Products
Review

Extech IAQ320 Review: CO2 and PM2.5 With Indicators You Can Read Across the Room

Two coloured bars on the sides of a display sound like a styling choice. In a classroom or an office they are the reason anybody acts on the reading.

By the Akermin Editorial Team · 3 min read

As an Amazon Associate, Akermin earns from qualifying purchases. Product links on this page are affiliate links.

Extech IAQ320 Review: CO2 and PM2.5 With Indicators You Can Read Across the Room

Extech · Extech IAQ320 Air Quality Meter/Datalogger with PM2.5

View on Amazon

Price and availability are shown on Amazon and can change at any time.

Verdict

The Extech IAQ320 covers the two indoor air parameters that actually lead to action, and presents them so that people other than the person holding it can see the result. The listing states simultaneous measurement and display of PM2.5, carbon dioxide, air temperature, relative humidity and a health index, datalogging, a large LED display readable across a room, and two side tri-colour LED bars indicating PM2.5 and CO2 levels. For a classroom, an office, a workshop or a survey, that combination is well judged.

Documented Specifications

Item Manufacturer listing
Parameters PM2.5, CO2, air temperature, relative humidity, health index
Display Large LED, readable across a room
Indicators Two side tri-colour LED bars for PM2.5 and CO2
Logging Datalogger
Presentation Simultaneous display of all parameters

The listing does not publish sensor types, ranges or accuracy for either the particulate or the carbon dioxide channel. For professional use, confirm the carbon dioxide sensing method on the datasheet, since that determines whether the measurement is optical or estimated.

Two Parameters, Two Different Actions

Carbon dioxide and particulates answer opposite questions and often imply opposite responses, which is why measuring both is more useful than measuring either well.

High carbon dioxide means the air is stale and under-ventilated. The response is to bring in outdoor air. High particulates mean the air is dirty. The response is to remove the source, filter, or, if the source is outdoors, to stop bringing outdoor air in.

A room can be high in both, and then the sequence matters: filter and extract at source first, ventilate second. A monitor showing only one of them can push you into making the other worse. See CO2 versus PM2.5 for ventilation.

Why Visible-From-Across-The-Room Matters

A monitor that must be picked up and read is consulted by one person who already cares. A large display with coloured bars is seen by everyone in the room, including the person nearest the window. In a classroom, an office or a meeting room, that is the difference between data and behaviour change.

Tri-colour bars also communicate without requiring anyone to know what 1,200 ppm means. Green, amber and red map onto do nothing, consider ventilating and open a window now, which is the entire decision most people need.

Treat the Health Index as Communication

A single index combining several parameters is convenient and lossy. It cannot tell you whether a poor score is caused by stale air or by dirty air, and those need different responses. Use the index to get attention and the underlying numbers to decide what to do. Any device that offers both is doing the right thing by showing the components alongside the summary.

Logging in a Shared Space

Recording a school day or an office day shows the build-up and recovery pattern that a spot reading cannot. A classroom that starts at outdoor background and reaches 2,000 ppm by mid morning is telling you the ventilation rate does not match the occupancy, and the shape of the curve tells you roughly by how much. That is the evidence a facilities manager can act on, and it is far more persuasive than a single alarming number.

Strengths

  • Both carbon dioxide and particulates in one instrument.
  • Readable across a room, so it changes behaviour.
  • Tri-colour bars that need no interpretation.
  • Datalogging for characterising a space over a day.

Limitations

  • No sensor types, ranges or accuracy published in the bullets.
  • Health index is derived rather than measured.
  • No radon or VOC measurement.
  • No logging capacity or interval range stated.

How It Compares

The Extech CO250 covers carbon dioxide with dew point and wet bulb but no particulates. The Temtop P600 covers PM2.5 and PM10 with a histogram but no carbon dioxide. Our ranking is in the air quality monitor roundup.

How We Research

All figures come from the manufacturer listing. We did not run laboratory tests and publish no measurements of our own.

Extech IAQ320 Air Quality Meter/Datalogger with PM2.5

Extech IAQ320 Air Quality Meter/Datalogger with PM2.5

View on Amazon
Extech CO250 Portable Air Quality CO2 Meter with Datalogger

Extech CO250 Portable Air Quality CO2 Meter with Datalogger

View on Amazon
Temtop P600 PM2.5 Monitor, Air Quality Monitor & Particle Counter

Temtop P600 PM2.5 Monitor, Air Quality Monitor & Particle Counter

View on Amazon

Products shown because their documented specifications fit this guide. Price and availability are on Amazon and can change.

Frequently Asked Questions

What does it measure?

The listing states PM2.5, carbon dioxide, air temperature, relative humidity and a health index, displayed simultaneously, with datalogging.

What are the side bars for?

The listing states two side tri-colour LED bars visually indicating PM2.5 and CO2 levels, so the status is readable from across the room without reading numbers.

Is the health index a measurement?

No. It is a derived summary of the measured parameters. Use the underlying PM2.5 and CO2 figures for any decision that matters, and treat the index as a communication aid.

Can it be used as a permanent display?

The large LED display readable across a room suggests exactly that use, and the datalogger means it can also produce a record while doing it.

Affiliate disclosure: Akermin earns a commission from qualifying Amazon purchases made through links on this page. Our editorial picks are based on documented specifications and owner feedback, not commissions.