Reading Temperature and Humidity on the Active Air Hygro-Thermometer
A jumbo LCD carries three things at once: the current reading, the historical high, and the historical low. Indoor temperature covers 14 to 122 F and the remote sensor covers -58 to 158 F, both to within about a degree. Humidity reads 25% to 98% RH at one point resolution, accurate to 3% through the middle of the range and 5% at the extremes. A stainless steel probe on a three meter lead does the outdoor half, and one AAA battery runs the whole thing. One battery, three readings, no wiring. The display auto switches between outdoor temperature and indoor humidity every five seconds, which you can turn off if the flicker bothers you.
Where a Hygro Thermometer Earns Its Place in a Grow Room
Placement is the whole game with a sensor like this. The head sits on a bench or hangs from a keyhole slot on the wall. A fold away stand props it at an angle you can read from across the room. Run the probe lead to wherever the number matters, which is usually canopy height rather than the floor where cold air pools. A lot of growers put the head near the door and the probe in the middle of the canopy. The max and min memory is what you check the morning after. It tells you how far the room drifted during lights out with nobody watching. One caution is worth stating plainly. The head itself is not built for standing water or constant condensation, so keep it off the tray and out of the spray path.
Key Features
- Jumbo LCD: Current reading, high and low sit on the screen together, readable from across a room.
- Three meter sensor lead: Puts the probe at canopy height while the display stays somewhere you can see it.
- Max and min memory: Shows the overnight drift you would otherwise have to sit in the room to catch.
- Stainless steel probe: Anticorrosion sensor tip holds up in the humidity a closed room runs at.
- Wall mount or fold away stand: A keyhole slot and a kickstand cover both bench and wall placement.
- Single AAA battery: Preinstalled and long running, so there is no wiring and no adapter to find.
Technical Specifications
| Specification | Value |
|---|---|
| Brand | Active Air |
| Model | Hygro-Thermometer |
| Part Number | HGIOHTJ |
| Indoor Temperature Range | 14 to 122 F, -10 to 50 C |
| Remote Temperature Range | -58 to 158 F, -50 to 70 C |
| Temperature Accuracy | Plus or minus 1 degree |
| Temperature Resolution | 0.1 degree |
| Humidity Range | 25% to 98% RH |
| Humidity Resolution | 1% RH |
| Humidity Accuracy | Plus or minus 3% RH from 50 to 80, plus or minus 5% outside that |
| Sensor Cable | 3 meters, stainless steel tip |
| Memory | Simultaneous max and min |
| Auto Switch | Outdoor temperature and indoor humidity every 5 seconds, can be disabled |
| Power | One 1.5V AAA battery, preinstalled |
| Unit Size | 9.0 x 5.0 x 1.3 in |
| Weight | 0.25 lbs |
| Mounting | Keyhole slot or fold-away stand |
| UPC | 638104106016 |