GAIN EXPRESS CO2 Meter Handheld CO2 Monitor 9999ppm Measuring Range Carbon Dioxide Detector NDIR Sensor Air Quality Temperature Humidity Meter

I bought the device to check for co2 levels inside my home. The instructions says that it should indicate 400ppm outside, and my test indicated 408ppm which is very close (the device could be recalibrated if necessary). The meter is slow reacting so you will need to leave it for about 10 min on a location in order to get a more accurate reading. So in summary, it has helped a lot in determining the areas that need more ventilation. The cons are the design and labels of the functions is confusing, to the point that you will need the instructions in hand to operate if you don't know how to use it. Also, it is very slippery so make sure is left on a flat surface and never up. Providing you can live with that, this meter accomplish it's function and given the price, I would definitely recommend it.

Meter arrived on time but out of the box the reading for CO2 was 978ppm opposed to the actual 519ppm measured from a calibrated professional meter. There is no way shown to calibrate to match the correct reading, the instructions say the meter was calibrated at the factory at 400ppm and the manual calibration button will only calibrate the meter if the CO2 ppm is at 400 in the room so I am not sure how it possible for end users to calibrate this machine without a chamber and co2/air mix facility. This meter is pretty much useless and a waste of time as delivered, would not recommend.

Purchased for my husband to use at work - perfect tool - does all it is supposed to and at a fraction of the price of the more expensive ones.

Good product very happy with this purchase

The item worked well and is an OEM or a brand who charge 3x the price here. The device works well and does the job!

Bought one of these to measure my climate changing environment. Measured my CO2 readings in my back garden 370ppm. Hmm thats odd. I live next to a main road, lots of cars so it should be higher. No still 370ppm in the back garden. Hmmm So i check where the "climatologists" measured their co2 reading of 407ppm. And i find its in Hawaii. And Hawaii if you didnt know if full of bloody volcanoes spewing out co2. The truth is you get readings from between 280ppm to 350ppm in rural areas. But buy one of these and check it for yourself. Oh and have a look at ice core records. 100,000 years ago, it was 350ppm. Thats why man made climate change is a hoax

Works well.

Epically fasr delivery. Actually bought the wrong monitor but the product itself is 10/10. Am going to give to someone who'll use it in their work.