Why it matters
The Extech 445580 Humidity and Temperature Pen is a temperature and humidity monitor with a stated temperature accuracy of 1 degree Celsius and a humidity range of 5% - 95% relative humidity.
A hygrometer tells you whether you need a humidifier or a dehumidifier: aim for 40 to 60 percent relative humidity indoors.
Price-wise it sat in the dearest third of the 25 hygrometer models we cover when we checked; the button shows today's price.
It qualifies for our list Best Hygrometers for Home, where it is ranked against every model that meets the same rule.
The listing gives dimensions of 1.2 inW x 1 inH and a weight of 0.07 kg.
Warranty, per the listing: 1 year.
Who it's for, and who should skip it
Good fit if
- Setting a humidifier or dehumidifier
Look elsewhere if
- Replacing a CO or smoke alarm
Pros and cons
Pros
- Temperature ±1 degree Celsius
Cons
- Readings need a few hours to settle after moving it
Limitations to weigh
- Not stated on the Extech 445580 Humidity and Temperature Pen listing: connectivity, power source. Ask the seller or check the manual before relying on it.
Specifications
The bracket shows where each figure comes from.
| Dimensions (seller) | 1.2"W x 1"H | Retailer |
|---|---|---|
| Product weight | 0.07 kg | Retailer |
| Mounting / installation | Tabletop | Retailer |
| Humidity range | 5% - 95% relative humidity | Retailer |
| Voltage | 3 volts | Retailer |
| Temperature accuracy | 1 degree Celsius | Retailer |
| Pack count | 1 | Retailer |
| Unit count | 1 Count | Retailer |
| Warranty | 1 year | Retailer |
| In the box | 445580, pocket clip, 2023 button battery | Retailer |
Alternatives worth comparing
More air quality monitors we cover
Final verdict
A sensible choice for setting a humidifier or dehumidifier. Confirm the model it fits before ordering.
Where to buy
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