SensorPush sensors are used in all kinds of places: wine cellars, freezers, greenhouses, humidors, crawl spaces and outdoors. Most of the time they're perfectly happy. But a few conditions can damage a sensor or make its readings unreliable, so it's worth knowing the limits before you place one somewhere demanding.
Temperature Limits
The HT1, HT.w and HTP.xw are designed to measure from -40°F to 140°F (-40°C to 60°C).
- Too hot: Saunas, ovens, smokers, dryers and the area right next to a heater are above this range. Attics, vehicles and anywhere in direct summer sun can also get hotter than 140°F (60°C).
- Too cold: Most home and commercial freezers are fine. Ultra-low freezers (for example -80°C lab freezers) and dry ice are well below the sensor's range.
If you need to measure temperatures outside this range, or the temperature of a liquid, our TC.x thermocouple sensor uses a probe and is designed for that kind of job.
Water and Rain
- The HT.w and HTP.xw are water-resistant. They have o-ring seals and a protective membrane over the sensing element, so splashes and rain won't hurt them.
- The HT1 is not water-resistant. It has a small opening so the humidity sensor can sample the air, so keep it dry and out of the rain.
- No SensorPush sensor is waterproof. Please don't submerge them or put them in a pool, hot tub, aquarium or anywhere they'll sit in standing water.
For outdoor use, see Can I use SensorPush sensors outdoors?
Condensation
Condensation is the one that surprises people. When the air is very humid and the temperature is close to its dew point, moisture can condense on any surface that's even slightly cooler than the air, including the inside of the sensor's case. Rain covers and water-resistant seals don't prevent this, because it's the air itself that's condensing.
Places where this often happens include greenhouses and grow tents that mist heavily, incubators, steam rooms, bathrooms, and outdoor spots where the humidity regularly climbs into the 90s near freezing. If your sensor will live in conditions like these, expect that it may not last as long as it would elsewhere. If readings suddenly go wrong after a stretch of very damp weather, see My sensor isn't working. Help! or contact us.
Very High Humidity
Even without condensation, spending a long time above 80% relative humidity can cause the humidity reading to drift up by as much as 3%. This is normal for this type of sensor, and it gradually goes away once the sensor spends time in drier air.
Cold and Batteries
Batteries work less efficiently in the cold, so a sensor in a freezer will need new batteries more often, perhaps every 6 to 12 months in a very cold freezer instead of every year or two. Freezer walls also reduce wireless range. See Can I use SensorPush in a refrigerator, freezer, or walk-in cooler? for tips.
When you move a sensor from room temperature into a freezer, give it at least 15 minutes to cool all the way through before trusting the reading.
Chemicals and Fumes
The humidity sensor can be affected by strong fumes and vapors. Containers that give off a lot of vapor, such as some humidors, curing jars and spaces with solvents or cleaning products, can cause humidity readings to drift over time. When cleaning a sensor, wipe the case with a slightly damp cloth, and avoid spraying cleaners or disinfectants directly onto it.
Not sure whether your setup is a good fit? Email us at support@sensorpush.com and tell us a little about where you'd like to use your sensor. We're happy to help.