Why it matters
The INKBIRDPLUS PTH-9A CO2 Monitor is a CO2 monitor.
CO2 is the best everyday signal of ventilation: outdoor air sits near 420 ppm, and indoor readings above about 1,000 ppm mean the room needs more fresh air.
Price-wise it sat in the middle third of the 11 co2 monitor models we cover when we checked; the button shows today's price.
It qualifies for our lists Best CO2 Monitors for Home, Best Air Quality Monitors, where it is ranked against every model that meets the same rule.
The listing gives dimensions of 4.72 x 3.15 x 1.57 inches.
Who it's for, and who should skip it
Good fit if
- Checking ventilation
Look elsewhere if
- Replacing a CO or smoke alarm
Pros and cons
Pros
- Co2 monitor
Cons
- Readings need a few hours to settle after moving it
Limitations to weigh
- Not stated on the INKBIRDPLUS PTH-9A CO2 Monitor listing: temperature accuracy, humidity range, connectivity, power source. Ask the seller or check the manual before relying on it.
Specifications
The bracket shows where each figure comes from.
| Model number | PTH-9A (6-in-One) | Retailer |
|---|---|---|
| Dimensions (seller) | 4.72 x 3.15 x 1.57 inches | Retailer |
Alternatives worth comparing
More air quality monitors we cover
Final verdict
A sensible choice for checking ventilation. Confirm the model it fits before ordering.
Where to buy
Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure