Temtop Air Quality Monitor with Indoor Thermometer & Thermo-Hygrometer – PM2.5, AQI, Temperature and Humidity Meter for Home, Office, Nursery, School, 60-Day Battery Life

Temtop
I’m getting pretty accurate readings for PM2.5 and AQL with my air purifiers and air humidifier. I also noticed a marked difference with my AC filter also

Good quality.
Let’s me know my current air quality in my apartment. Does a good job.

a little buggy, but still useful
Update #4: The company sent me another one so I could corroborate the readings of the unit I bought. I did several quick tests in various locations and in nearly all cases I got the same reading on both, or very close. However the photos show one case where the readings seemed to get stuck and after waiting about 40 minutes (note the times on the microwave) the readings were still different in this one test. The last photo was taken after I turned both devices off then back on, and in that case they settled on the same reading. Basically, the flaw with these units is that they will sometimes get stuck on an inaccurate reading… but in most cases if you turn it off then back on you will get a different and presumably more accurate reading. Overall I’d say these are accurate enough to be useful, as long as you don’t mind confirming the reading by turning the device off then back on.Update #3: I continue to have trouble with the device. It shows an accurate reading in some cases, but only shortly after it is turned on. Then it just fixates on that reading regardless of changing conditions. I have confirmed this issue repeatedly by turning it off and on after it gets stuck, and almost without exception it will settle on a much different reading after it is turned off and then back on. Meanwhile, the manufacturer has offered to send me a new device, which I do appreciate, and I will update my rating if they are able to follow through and if the replacement works better than the one I have now.Update #2: It kind of works but has a tendency to get stuck on readings a minute or two after you turn it on, and then the reading doesn’t change even if you move it to a location where the air quality is obviously different. This can be confirmed by turning it off then back on, which will often cause it to reset to what is likely a more accurate reading. It does seem to respond to changes in air quality, so long as you turn it off then back on. The ECO (power-saving) mode doesn’t work, or it is always on regardless of whether you turn it on or off. There is no change in behavior depending on whether you turn the power-saving mode on or off. Either way, it tends to get stuck on a reading, sometimes, a minute or two after you turn it on. But not always. Sometimes it won’t get stuck until 15 minutes after you turn it on, sometimes it is responsive for a few hours, etc.Update: Still doesn’t seem to be working. Today it was showing a PM2.5 reading of 22 in location #1, outside. I then moved it inside, to location #2. An hour later it still showed 22. I then turned it off and back on, and left it in location #2. It then read 15, and is staying at 14-15. So how did the PM2.5 decrease by 33% just because I turned it off and on? I didn’t disturb the air in that area very much when I turned it off and then back on. I didn’t waive it around or anything. So how could pushing a button twice change the PM2.5 by 33%?Original review: Received this item in the mail today. When I first turned it on, and for a few hours after that, the PM2.5 and AQI seemed quite plausible, and I figured the device was working well. A few hours after that, I looked at the device, and in the same location, on my nightstand, it was now reporting PM2.5 had increased by 10x and the AQI had gone from in the 30s to above 140. This is totally implausible. There has been no change in the environment that would explain this. All weather sites and other online sources report air quality readings consistent with what the device was showing earlier in the day. I tried moving the device outside, etc. Turning it off and on, and the readings are still implausible high. I have done no nearby cooking, showering, etc, or anything else that could have affected the device.Meanwhile, when I switch it to ECO mode, the PM2.5 continues to move up and down, even though this mode is supposed to only test PM2.5 once every 30 minutes. Earlier today it was working, but inexplicably the PM2.5 now fluctuates even when in ECO mode.And for what it’s worth, the Amazon listing for this item says the company is “based in USA,” but unsurprisingly, the device itself says it is made in China. Not that the Chinese are incapable of making anything good, but this particular Chinese manufacturer appears to have failed.

disappointed with product – stagnant/inaccurate readings
I’ve had this for a week, and one think I’ve noticed is that the readings (PM2.5, AQ1) just get stuck and don’t change for a long time .. when I restart the device, the readings change and seem to be correct (though i’m not sure of the accuracy) … after using this for a week, I’m not sure if the reading is accurate.. overall i’m really disappointed with this product, will probably return this.

This air quality monitor is working perfectly fine. I have seen some comments saying that it is not stable but I have tested it in multiple scenarios and it is working perfectly fine. I have recently bought an air purifier. Before turning on the air purifier the AQI was around 85 in my room. After 10 minutes of running the air purifier at full speed the value dropped to 25. I also tried it in multiple places during multiple days and the values looked consistent. I think this is a genuine product. I am attaching a few images captured at different locations.The only problem I noticed is when we use it directly under the sunlight it is giving a lesser AQI value. I think they have also mentioned this point in their manual, saying that direct exposure to a light source can alter the values. That is the only issue I found with it but for internal use cases it is great and really content and the battery life is so good. I have been using it for almost one week and even a single bar has dropped on it. Just to clarify I have been only using it on and off for short durations to test the AQI. I haven’t left it turned on but even with this I think the battery life is really good.

It’s a good air quality monitor but it updates in real time only when it is plugged-in. Though the battery lasts very long, the PM2.5 and AQI readings take a lot of time to update (more than a few minutes). Temperature updates in seconds even on battery. You have to keep it plugged-in if you want to see PM2.5 and AQI getting updated in seconds. Have compared with readings on air purifier and the readings are close, so appears to be accurate with 10% error as claimed.