CO2 Meter Portable CO2 Detector Digital CO2 Monitor with Alarm Function Carbon Dioxide Temperature and Humidity Meter, NDIR CO2 Sensor Indoor Air Quality Monitor for Home Office Grow Room

I have been having what I assume is an exhaust leak in my car. However I have a very sensitive sense of smell and I didn't want to spend a lot of my time and effort fixing what may be a very small problem. Initially I tried a CO meter however the meter itself was defective. On further investigation I determined that a CO meter was not what I needed anyway. Most modern cars do not output very much CO at all. The catalytic converter converts most CO to CO2 or water. Also, trying to detect CO means detecting a few parts per million. That's difficult. With a CO2 meter it's much easier because any decent sized exhaust leak will VERY quickly spike the CO2 levels in the car. Also, the measurements will be in the 1000s of parts per million so the error range of the meter is less important. In short, if you're looking for exhaust leaks in vehicles it will likely be easier with a CO2 meter as car exhaust is chock full of CO2. On to this meter, it works very well. I tested it in a number of situations and it detected the amount of CO2 that i would expect it to. The manual states that it samples the air once a second and as far as i can tell this is accurate. However, it is not meant to precisely measure the CO2 concentration every second. The sensor takes time to accurately reflect the ambient CO2 level. This is easy enough to test by breathing briefly on the sensor which will cause it to easily jump to over 5000ppm but it will take 30 or more seconds to return to normal. In my own car I found that the CO2 level was no different from my friend's car. So whatever I'm smelling on hard acceleration it is very likely not exhaust gases or is such a tiny amount that it's not adding to CO2 levels. That is a helpful thing for me to know. Further, this meter has applications beyond just testing the cabin of a car. It can also be used in buildings to determine if the amount of ventilation is adequate. Also, it can be used in the home to see if CO2 levels are too high (as can occur particularly when cooking or using a fireplace). I was surprised to see that in both my car and my friend's car, with the air on recirculate, we reached over 1500ppm in just a few minutes. It comes in a cute carrying case that looks like a tiny plastic briefcase. I can't imagine I'd ever use it but if you want to look like a real "pro" it can't hurt to have your meter in it's own case.

I bought this CO2 meter to measure both building health and "other things" of current concern in 2020. The meter appears accurate (fresh air gives 425ppm, which is very close to the current global average of 400ppm). Some might find the meter's user interface is a bit annoying, but anyone who's used a digital multimeter will get use to it right away - same idea of modal buttons as most modern digital multimeters. An important gotcha to be aware of is the CO2 measurement appears to take about 3 minutes to settle on a value. For example, stick it under an N95 mask, let it max out at 10,000 ppm, and then put it under a fresh breeze. It'll take a minute or two to settle back to normal fresh air values. This isn't a show stopper, you just need to be aware of it. If you make a change in the environment wait 3 minutes to measure before you make another change or record the measurement. From the behavior I'd guess they have a very long averaging window for CO2. The RH and temperature measurements settle much more quickly - 10 seconds roughly. Not like my 1 second meat thermometer, but certainly good enough for any building sickness application.

Love how this helps us locate co2 leaks.

It's easy to use and or the price is as accurate as most of us will ever need.

Seemed to work for a few months. Then, after some very high readings (1400+), I decided to check against outside air, which showed as around 700ppm. So, I pressed the button combo for recalibration (although, this is so wrong that it shouldn't need 'recalibration' to be in the ballpark...) Anyway, the button combo didn't work, won't go into recalibration mode. Just says 700ppm more or less for outside air. I am in rural Vermont; I don't think so...

Product looks good for the price, it worked right out of the box once the batteries were added, and its measurements appear to be accurate against my other meter. Great Value.

First of all...this works really well. Very sensitive and responsive to changes in the CO2 levels nearby. I bought it for some experimemts with ridiculous "face coverings". Sitting outside the CO2 concentration in the ambient air was around 500 ppm. Holding the monitor near my nose I had readings anywhere from 1500 to peaks near 2800 ppm. With a basic sewn cloth mask...holding the monitor in the same location the reading hit 9,999 ppm in a minute or two. That's the limit on the meter. CO2 levels topped out, I have NO idea how high it got beyond 10,000 ppm. A paper mask they hand out at stores (besides having to breathe in what ever chemicals that are in the paper) didn't fare much better with regards to holding in CO2. The paper mask passed 10k ppm as well it just took another minute or so. I also tested a loose fitting linen mask that I made (I reviewed the material on amazon). Amazingly, that mask does not appear to reduce O2 availability. All other masks I've tried DO reduce O2 availability inside the mask to levels below OSHA standards of 19.5%. I know because I bought a quality O2 meter and performed many tests. Even my linen mask which does not noticeably reduce O2 percentage, did hold some CO2. I saw levels consistently around 2200-2400 ppm, with peaks over 3500 ppm. My tests prove conclusively for me that most face coverings that the crowd has been guilted into wearing...DO seriously degrade the quality and safety of the air brethed in by the wearer. One excerpt about air quality guidelines: CO2 at 2,000-5,000 ppm can result in: Headaches, sleepiness and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present. But, "do your duty" right?

Worked perfectly right out of the box. No calibration needed. Outside co2 was 401.