NOTES ON INDOOR AIR MONITORS
A product title
is a list.
Not a sensor.
How published sources separate NDIR carbon dioxide from eCO₂, particles from gases, and a snapshot from a day — and why a consumer reading still does not decide whether a room is safe.
Source-based notes for small UK households and bench users who already have, or are about to use, an indoor air monitor. AirMeasure UK is not a certification body.
WHAT THIS SITE DOES
What is the difference between a product title and a sensor?
A product title can list PM2.5, carbon dioxide, TVOC and HCHO as words on a shop page. A sensor is a named measurement principle: laser scattering, NDIR, photoacoustic detection, an electrochemical cell, or a metal-oxide film. These notes keep that distinction, using published engineer logs, sensor tutorials and the HSE workplace page. AirMeasure UK is not a certification body. This publication has not published original room series, and a consumer reading is not a medical result.
| What you can read | What it can support |
|---|---|
| A shop title | A list of words. It does not name a measurement principle. |
| A named sensor | Laser scattering, NDIR, photoacoustic, electrochemical or metal-oxide. |
| A consumer reading | A number on that instrument. Not a medical result. |
Sensor notes
Title versus body, true CO₂ versus eCO₂, particles versus gases, and the limits of low-cost TVOC and HCHO.
Open the sensor notes ↗02 / THE ROOMVentilation notes
HSE placement, a snapshot that is not the day, and why ABC assumes about 400 ppm.
Open the ventilation notes ↗03 / THE EVENTParticle notes
How to log cooking and open windows so a laser reading stays a trend.
Open the particle notes ↗START WITH THESE NOTES
Which note explains the instrument, the room and the event?
The sensor notes separate a catalogue title from a named principle, true carbon dioxide from an eCO₂ estimate, and particles from gases. The ventilation notes quote HSE placement, one snapshot against a full day, and the 400 ppm ABC assumption. The particle notes explain how a cooking or window event is written beside a laser reading so the number stays a trend. Related shops stay on the disclosure page. They are not used here as verified instruments.
- The sensor type is named.
- The event log stays with the reading.
- The health column stays empty.
Source-based noteA product title is not a sensor
Four related retail listings name PM2.5, CO₂ or HCHO in the title. Only the body text, and only where it names a principle, can be treated as a clue.
8 MIN READ ↗
Source-based noteTrue carbon dioxide is not eCO₂
NDIR and photoacoustic sensors measure carbon dioxide. SGP30-style eCO₂ estimates it from volatile organics. The two numbers do not answer the same question.
8 MIN READ ↗
Source-based noteParticles and gases are different sensors
A laser counts scattered particles. Infrared, electrochemical and metal-oxide sensors look at gases. A cooking spike is a particle event until a gas sensor of a named type is also in the log.
7 MIN READ ↗READ THE CLAIM. SEE THE SOURCE.
Are these pages AirMeasure UK measurements?
These pages are not AirMeasure UK measurements. Figures from HSE, RevK, Jeff Geerling, Tyler Cipriani, Adafruit, Yoctopuce and AirGradient stay attached to those publishers and to the conditions they wrote down. A shop title that prints carbon dioxide is not treated as an NDIR or photoacoustic instrument. A consumer reading is not a medical result. The distinction between NDIR and an SGP30-style estimate is set out on the Adafruit SCD-30 page.