Portable CO2 Meter Handheld CO2 Detector Monitor 0~9999ppm, Carbon Dioxide Meter with Alarm Function, Temperature & Humidity Meter NDIR Sensor Air Quality Monitor for Home Trip Classroom and Office

Indispensable instrument in this time of pandemic to ensure that your environment is adequately ventilated. I’m glad I bought this; my tightly sealed house had a reading of 1600 PPM CO2 and this meter clearly shows when the windows have been opened long enough to bring CO2 down to a healthier level of 600 to 800 ppm. Buy this if you want to look like a contractor. It’s ginormous and yelliw but actually light weight, especially for the size. C02 reading comes up in 30 seconds after a countdown; initial indoor relative humidity indoors after unit is outdoors takes a while to stabilize maybe ten or 15 minutes. The toggle between air, wet bulb, and dew point temperature is nice; kind of wish it also showed heat index. Now the bad: Terrible human factors design; without the manual you’d never figure this thing out - fortunately the tiny manual explains it all pretty well. Don’t lose the manual. Buttons are excessively debounced to the point that sometimes a button press isn’t recognized. A RS232 interface??? Stone age technology and forget about using your phone to log data. Alarm initially set to 1000 PPM probably isn’t a good choice; if you take this to your local grocery store or neighborhood bar or school or workplace and make a measurement that’s above this strict limit you’ll freak everyone out. It’s easily changed (but don’t forget the manual) I would buy this again. It works well. I like it.

We've bought several of these over the years and they are workhorses. Alway work, battery lasts forever, accurate and consistent.

Used to measure CO2 ppm in a space heated by kerosene. The meter instructions says it is factory calibrated at 400 ppm. It read 432 in the outside air. I don't understand people's issues with the manual. It is easy to read. The calibration instructions are clear but yes you do need the manual. I have not check the accuracy with test gas as those test cylinders are ~ $200. Regarding the calibration procedure and for the fear of losing the manual. Take a picture of that paragraph and put it in the case. Potential problem addressed.

If you want to know whether your are living/working in fresh or stale air, this is the perfect tool. It is not a cheap purchase, but quality is rarely cheap. I love mine and wish more people were cognizant of air quality (which makes a difference during cold/flu/air-borne pandemic season). Great item.

Works as described

Like that it's handheld and comes with a case although case is really oversized for the device. Device easy to set up. But need to read the instruction manual since there are abbreviations not necessarily obvious. would be nice if it comes with calibrating salts. But it does come with batteries.

Bought "used like new." No operation manual included.

I am using it in my work station and it gave me accurate readings. I have used different CO2 testers before and this one is the best one so far. It is easy to use and user-friendly. I tried some of the cheap CO2 testers in the past and I feel much more confident with this new tester. It's well worth the money and I strongly recommend it.