Originally published at: https://breathesafeair.com/temtop-m10-review/
A couple of weeks ago, I received another monitor from a brand that I’d been meaning to try for a long time. This time, it was Temtop, a brand that I’ve been interested in quite a lot over the years, as I often see its monitors mentioned in discussions on the best air quality monitors. While its range of hand-held particle counters appears to be the ‘flagship’ product line, it also has an extensive range of consumer-orientated household air quality monitors. In today’s review, I will look at the monitor atop this range of monitors, the Temtop M10+. This is…
Thanks for reviewing the M10+. I’ve used Temtop monitors in the past (the M2000c) and they seemed reliable, but I liked the size and battery life of this one, and your endorsement convinced me that it was worth trying it out.
Having used it for a couple days, I must say I’m baffled by some of the results, which don’t seem like what you got at all.
PM2.5 readings seem to fluctuate between much lower than I expected and outrageously high (eg, 999, which should be an error. CO2 readings seem a bit implausible when moving between different environments such as transport and different buildings, as a full train carriage shouldn’t have a CO2 of 750 and an empty train platform a CO2 of 2500. My suspicion is that the CO2 isn’t updating frequently enough, at least not when running on battery. The data export at the end of the day seems to show an hourly CO2 reading, which would be nearly useless for my purposes. In your review you mention frequent CO2 updates, so I’m wondering if maybe there is a hidden setting, or did I just get a dud device.
You also mention some functionality that appears to be either missing or very well hidden, such as setting offsets for temp and PM. Though I doubt I’ll be using this, it still seemed odd that it was missing.
Thanks again for your review.
Hi @OddLion, thank you for joining! I’m sorry that the M10+ hasn’t turned out to be very good though, especially as you partially bought it due to my review. I feel really bad about I hope you’re able to figure out what the issue is!
This seems like it can’t be anything other than a faulty sensor (or something inside the sensor). I’ve never seen anything close to 999 on my monitor, and if it’s that high you would notice very, very quickly! I would recommend reaching out to them to see if a replacement is possible. If you want to try something first, it could be worth trying to blow some compressed air through the vents at the back of the device to see if it helps.
This also seems very odd and is completely different to what I experienced with the device (which I found to give similar readings to my Aranet4). It also uses the SCD4x sensor which is a well-trusted sensor that performs well. I would guess that it’s miscalibrated, but that doesn’t explain the high readings on the train platform. Out of curiosity, how soon did you take the reading after getting off the train?
I’ve been using the device a bit more, and I have a feeling it only takes a real measurement every minute (or less frequently) and the ‘readings’ in between are only updates that trend in the direction of the previous readings. This would make it seem like the device is updating frequently, but it’s actually only taking a real reading every minute (for example, perhaps it’s less frequent), and this could explain the incorrect readings you are seeing. This is just a theory I have at the moment, but I’ve seen this on devices like the Vitalight Mini CO2 Detector.
With this said, even if this is the case, I would have expected to pick up on it in my testing… I will reach out to Temtop, because we need to know the answer to these questions.
This is also very surprising… this is the M10+, right?
I’ll do my best to help, and again, I’m very sorry your device hasn’t turned out as you expected (and as I experienced with my device). I’ll reach out to Temtop in regards to this to see if we can get to the bottom of this!
Hi @Ethan, and thanks for your long reply. There’s no need for you to feel bad, and I am of course not blaming you for your positive review. The M10+ design and possibly algorithm is most likely the cause of these glitches, unless it is a faulty unit in which case it is just bad luck.
I had a very interesting exchange with Temtop this morning about this, and it seems likely that the erratic readings are due to what they are calling “intelligent monitoring” - here is their reply:
If plugged in, it is real-time monitoring. If unplugged, it is intelligent monitoring. When the environment changes, the sampling interval is short. When the environment is stable, the sampling interval is long.
Of course this doesn’t explain the 5000 CO2 and 999.9 PM2.5 readings, but possibly their algorithm freaks out when the device is moved from one environment to another (eg, a train carriage to the platform). Still, I can see no reason why it would read 700 for many minutes inside a crowded train unless it is not updating, something they didn’t seem willing to acknowledge (at least not yet).
I may have to return it, but in any case hopefully this rather poorly controlled experiment will reveal something about how the device is functioning. I suspect they have programmed it to maximise battery life, but they should definitely be transparent and ideally allow the user to control such things. A firmware update that allowed the end user to set the frequency of refresh wouldn’t be hard, but I somehow doubt they will listen to me - maybe you would have better luck?
Thanks again for your reply, and I will certainly update you with any futher information I get (I have asked for more details).
This is very interesting, and perhaps worrying. I’ve actually also asked about this ‘intelligent monitoring’ (on another monitor), but I’m unsure how it works. If it’s not taking regular PM readings, how can the device tell the environment is changing? This could be based on any of the other readings (CO2, temp, RH, etc), but there are also situations where those don’t change but PM does. This seems like it could be quite a flaw with the device. I had just assumed the measurement intervals were very long when on battery.
I agree. Even if their ‘intelligent’ algorithm is flawed, it shouldn’t lead to such high readings. I have two Temtop monitors currently (the M10+ and the S1+) and neither have ever shown such extreme concentrations, so I feel like this is still a hardware issue.
Again, I totally agree with this. Transparency is key, and I wish there was an option (that the user could change) to change reading frequency. Personally, I wouldn’t mind if the battery life is only 12 hours, as long as I can get regular readings. This shouldn’t be hard to change, so I don’t see why it isn’t user adjustable. I will definitely make this suggestion to their team!