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.

From the SPECIFICATION, the CO2 readings must be increased by 1.6% for each kPa below normal pressure (101.33 kPa). At an altitude of 1000 feet (above sea level) the pressure is 97.717 kPa so the readings must be multiplied by 1.0578 101.33 – 97.717 = 3.613 3.613 x 1.6 = 5.78 The meter instructions say regularly calibrate it and they say it can be calibrated outside in well ventilated sunny weather. But, an accurate calibration outside probably isn’t possible. The meter instructions say it can be calibrated outside but it also says the CO2 concentration must be 400 ppm where the calibration occurs. The calibration instructions don’t mention that the calibration would need to be done at sea level and they don’t mention 400 ppm probably doesn’t occur at sea level in the northern hemisphere. If 400 ppm occurred at sea level and if the calibration was done at 1000 feet altitude, then an error of 5.78% would occur in the meter after the calibration. The lowest dry mole fraction of CO2 in the northern hemisphere may be at a remote location like Mauna Loa. 420.85 ppm CO2 was the Daily Average dry mole fraction at Mauna Loa February 24 2022. It can be 500 ppm in a city like New York. Mauna Loa is the only place I could find with daily CO2 measurements. The last time it was 400 ppm at Mauna Loa was around 2015. The dry mole fraction doesn’t vary with altitude but the concentration does vary with altitude (from “How we measure background CO2 levels on Mauna Loa”). So, the meter must be measuring the concentration since the readings must be adjusted if it isn’t used at sea level.

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.

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.

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

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.

まだ使ってないが試したら使いやすそうだ

mide bien y esta bien de precio

Compré el producto para medir CO2 de manera continua en el laboratorio, sin embargo no pude conseguir el software y cables adicionales. Tuve que comprar otro equipo de otra marca.

We have had to use this product two or three times since purchase and it has works exactly as advertised. Gave us readings and action to take accordingly. Easily portable which is nice as well. Don’t charge a battery in a closed space or leave a bucket of hot ashes in your house.

works well, but it is a bit pricey, though