Review on UEi Test Instruments CO71A Handheld Digital Carbon Monoxide Detector, Portable CO Meter with 0-999ppm Range, Visual and Audible Alerts, CO Monitor Tester + Battery Included by Bob Randles

I had this relatively recently. I am retired but still working as an Air Pollution Control Chemist with a background in Industrial Hygiene. I have access to much more expensive carbon monoxide meters. I plan to test the calibration more thoroughly but thought I'd share this quick review. I prepared a simple calibration standard by injecting a small measured amount of pure CO (4 mL) from a gas cylinder into a known volume of air (small 6.9 liter box). Its concentration should have been around 580 ppm and the monitor read 572 ppm. For the first test I was very satisfied as it is a one point and quick calibration test. Calibration will be announced later. I then used a CO meter in a high school demonstration to simulate burning a carbonaceous fuel (I used a small stick of incense for the lesson) in the atmosphere (represented by a small can). I lit the incense and put it in the jar along with the CO meter along with the carbon fuel burning toy car and put the lid on the jar. After a few minutes, the CO meter facing the students quickly rose to a surprisingly high reading (I understand few people can burn incense sticks in a 2 liter jar and breathe. Everyone enjoyed it. I'll keep an eye on it further update review in the next few weeks