Air Quality Monitor Accurate Tester for CO2 Formaldehyde(HCHO) TVOC PM2.5/PM10 Multifunctional Air Gas Detector Real Time Data&Mean Value Recording for Home Office and Various Occasion-Silver

This has been a lifesaver. My job has been re-circulating exhaust gas from cooking equipment to heat the place. This proved I’m not crazy and put them in a position to need to make change. My only complaint is I wish it could connect via Bluetooth to a phone to record data over time.

I purchased to monitor air quality in an occupied basement with an HVAC system, water heater and sump pump. Had two of these, one returned because one of its LEDs wasn't working correctly. While both were in use, the readings were in agreement and seemed to fluctuate as expected when environmental conditions changed. The instructions are bare minimum so plan on doing a little research to learn exactly what you're looking at if you're not already familiar.Two things I don't like. First, why put the power cord port on the side for a tabletop model? Should be on the back to hide the cord. Second is a high-pitched squeal after it's plugged in long-term. It takes a couple weeks for that to happen but the easy fix is to unplug the cord and let the battery run down before plugging back in. Probably good to do for the battery anyway.Initially, I got impatient with it, thinking it was defective. If you do purchase, make sure you let the unit do its thing for a while before expecting a good reading. It goes a little crazy on its first use or after a reset. Don't worry - it'll level off eventually.

Bought for checking air quality in home. Reading were constantly changing from one minute to the next as in super small to super dangerous then back. Could never determine what actual air ratings were. Battery charge was super low as well. If you want true ratings, buy something else.

Display information is unclear as to meanings. What is good or ok?

1. the instructions state that the device needs 120 seconds to reach operational temp, it left out the part that it starts counting for you.2. Readings are real, they respond to breath, and blowing air, etc....3. not a bad beginner device, if you aren't sure how much to spend on an air quality detector.

Tested this device with my breath and it states I am emitting a deadly amount of 800ppm CO out of my mouth. Granted my breath may not be minty fresh, buts its not that deadly. This part of the sensor isn't correct. I'm not setting off carbon monoxide alarms just by breathing onto one..I'm not giving it a totally bad rating. After the breath test I gave a fart test, and the TVOC levels did respond accordingly, so did my GF.CO2 levels seem to be on target, 400 to 600ppm most of the time, goes up when using the gas stove. I have no calibrated instrument to compare against though.Very easy to use and responds fairly quickly after a couple minutes of wait time when first turned on. Very reasonable cost compared to some, potentially more accurate, sensors. USB charging. Unlike some have stated, the readings on my unit do not jump up when plugged in to charge. It's plugged into a laptop, maybe the cheap little USB power bricks that plug into an outlet have an AC component in the power that affects the readings.

This is a very cool device but the instructions are basically non-existent. It doesn’t explain what any of the readings are for and the table it provides to show what the ideal measurements would be is formatted as to be unreadable. Had to do way to much outside research on air quality to even begin to know how to use this.

I bought it for two reasons:1. To locate an exhaust leak in a classic VW Beetle. I thought it was a leak in one side of the heat boxes but it turned out to be leaked exhaust sucked into the fresh air intake. It would have been impossible to track without this meter.2. To determine if my home office had sufficient ventilation (it turns out it didn't).It's easy to use. Appears to be accurate but it's not a super portable device so it's more accurate when left alone untouched for some minutes.The CO and CO2 readings typically react within 5-10 seconds of changing conditions, like opening a window.What I would pay more for, in a prioritized list:1. I wish it was wireless with an app that I could set alarms with trigger levels in.2. I wish it had a wifi connection and a cloud service so I could monitor a space from afar.3. I'd like a color display that could show health hazard levels more easily.4. I'd like more air quality readings like radon and also a simple temperature and humidity reading.

Even after 3 days and keeping it switched on for hours, it can not show correct AQI.Very fancy looking view lured me into buying a totally useless device. Total waste of money , go for other AQI readers.