Indoor Air Quality Monitor, IGERESS Formaldehyde Detector, Pollution Monitor，Dust Tester, Detect Indoor HCHO/TVOC/PM2.5/PM10, Colorful LCD Screen & USB Charging

Based on my experience, I definitely recommend this device. It's easy to calibrate -- the directions are extremely clear. You basically just take it outside in clean air for five minutes and follow the instructions on the screen. When I finished calibrating it and brought it inside, the numbers for HCHO and TVOC jumped quite high initially, but then slowly came back down to the actual level.As the instructions suggest, it's best to leave the device in a room for at least 5 minutes to get an accurate reading, as the numbers climb/fall quite slowly. Also, I noticed the numbers climbed a bit when I held the device in my hand or breathed near it, and fell when I walked from room to room (maybe due to the 'breeze' of walking). So just set it down somewhere for 5 minutes to get an accurate reading.I tested the consistency by bringing the device outside again after testing each room in my house. As soon as I brought it outside, levels dropped to 0.000. When I came inside, the HCHO and TVOC numbers rose. I re-tested each room and got nearly the same results as the first time, give or take 0.002 mg/m3.Now, I suppose there is really no way to test the accuracy without comparing it to another product's test results, but I feel confident that the levels are more or less accurate, just based on our home's general ventilation and materials used. If I do test indoor air quality using another product in the future, I will update this review to reflect that data.

Love the ease of use and the ability to visit customers and show them the quality of their indoor air. Opens their eyes to what they are breathing.

My title needs some explanation. I have tried several of these home "air quality" meters now which purport to measure contaminants but all share a common weakness. They all require "calibration" which is basically taking the unit outside and running a special step to zero it out. This is where the problem lies. They all seem to be extremely sensitive to the conditions "outside" to determine what they will read inside. Not just the air quality but the temperature and humidity seem to play a role on how the readings inside your home will be affected. As an example, one time I calibrated the unit in the early morning when it was cold and dry outside and when I brought it inside and the readings settled down they were significantly different than they were based upon the calibration the evening before when it was warm and humid. I assume my outside air has negligible levels of formaldehyde and TOC but of course that would affect it too. If you have contaminated air outside then using it to calibrate the meter will only result in a relative reading, not an absolute one. Also, the differences can be so dramatically different it makes you question just how accurate any of these are. They do have some usefulness in that they will react to contaminants and show by means of change of readings what areas are "more contaminated" than others but that's a far cry from being able to believe their readings are accurate.This model does seem to be pretty consistent and I joke that it is precise, if not accurate (meaning it reads to 3 decimal places but the reading probably means nothing because if you recalibrate it you can get vastly different readings right afterwards. even though it was just calibrated a few hours before. Case in point, I calibrated it this morning and was seeing TVOC reading close to the top of the scale (9.999 mg/m3) which I knew could not be right so I took it outside and recalibrated it and now it reads 0.590, almost 1/20th of what it read prior to recalibration. So which reading is accurate? Probably neither. But if the meter goes up it probably means there is more contamination than there was before. You just can't trust the numbers.Also, certain household chemicals will fool both meters. Lighter fluid will pin the TVOC meter but has no real effect on the HCHO level while alcohol (both rubbing and drinking) will increase the HCHO level and the TVOC level. Who knows how many other commonly found chemicals and cleaners will move the meter. So you really aren't measuring pure HCHO with it.My advice is if you are really seriously concerned about indoor air quality you should probably contact an expert and have the air samples tested by a real laboratory. None of the meters is really useful to tell you if your home is contaminated or not.They are fun to play with though.

This device does exactly what it promises: it is easy to calibrate and once done so, reliable, stable readings can be achieved in 5 minutes or so. The readings are consistent and seemingly accurate. Using it is very straightforward, with minimal configuration necessary (just needed to set the time and calibrate it).Overall, for around $100 this is a great option if you want to check your air quality for peace of mind. Certainly done the job for me to check air quality after installing spray foam insulation.

Hard to use and understand and as far as it’s accuracy it doesn’t seems to be accurate . After attempting to calibrate this the reading seem inaccurate. it really shouldn’t need calibration should come calibrated. The pm 2.5 and pm 10 can’t be right. They are the same and too low. After trying to set the Calendar it started at 2015 so this must be from 4 years ago. Returned for refund.

Directions are extremely confusing and foreign. The machine, however, is very inclusive and efficient. A great value compared to other similar detectors.

I paint with oils and have for years been breathing in all the VOC's, off gasing from the paints! I can now monitor my studio and make sure the air is fit to breath. This and the whole house fan have made my life better and prevented me from having major medical issues! Should have had the monitor years ago!!!!!