VQP Multifunctional Air Quality Monitor, Intelligent O3 Ozone Detector Analyzer, Portable Outdoor Indoor Air Quality Meter, Temperature Humidity Gauge with LCD Screen, Adjustable Alarm Threshold

What else is there to say. It works and it was the cheapest one out there. No frills though

I will return this item for two reasons.1. The O3 dectector I received does not work. The display constantly displays a random value in the range of 0.00 to 0.03 ppm with an update about every second. It does not appear to be actually reading or displaying actual O3 readings in the atmosphere.2. The device will only display readings in increments of 0.01 ppm, which is 10 ppb. Local air quality standards state that 0.07 ppm is approaching the first warning level and 0.10 is very unhealthy. The lowest alarm setting is 1.0 ppm (1000 ppb). That is 10 times more than the standard and twice as high as a rating of extremely unhealthy (500 ppb).

Purchased two of these. One shows an average constant reading of 3.5ppm the other one shows 0.1ppm. Both right next to each other. Which one is right? Probably the second one because if it’s the first one we would feel really sick.How can the product vary this much?

According to the instructions: The minimum alarm setting is 10 times the maximum safe level Ozone. The alarm can only be set to 1.00 ppm minimum. So as long as you don’t mind being alerted when the ozone level is already 10 times the maximum safe level this one is for you. According to OSHA the maximum average safe limit is 0.1 ppm over an 8 hour time period.

We bought this to measure ozone in an industrial setting to measure ozone and it is not accurate at all. I do not recommend this