There was a time when reviews of products actually meant something . We are all too familiar with journals and magazines promoting products that their magazine had the manufacturer as their main advertiser or sponsor. A classic example of this is hifi magazines.
Not good , not fair, however at least people writing the article had a good knowledge of the product and a deep seated interest.
Where we used to apply BS kite marked standards to products, now it is a free for all.
With regards to Air Quality Monitoring, new low cost sensors mean that the technology suddenly becomes affordable. Cheap is one thing but reporting accurately is another.
Normally when a product is built, it is designed to meet a standard. In this case an air quality or indoor air quality standard. However we don;t have an indoor air quality standard for homes or buildings. The BS ambient atmospheres is working towards a standard but it is slow whilst chaos around them ensues. The nearest thing we have is a mixture of part F of the building regulations looking at NO2, CO and TVOC
And now here is the rub. So in all of the reviews – no one – yes – NO ONE performs any validation testing. Either against a reference standard test gas or a secondary standard monitor.
One chap reported that ” the temperature was 6 degrees out, but other than that it worked fine” !!!! A 8 year old school could good make a device with an accuracy to 0.1 degree. So the guy was happy measuring the device against something he though might be accurate. But was clueless in understanding if :
b, what a correct reading would be anyway
For the record i am adding some guideline values here. This is difficult to source as many organisations and countries use different reporting criteris > ie 15mins , 1 hour , 8 hours etc
NO2 150ppb – 8 hour average
CO- 90ppm 15m average
CO 10ppm 8 hour average
TVOC 300ug/m3 8 hour average
CO2 – 400 -1400 8 hour average
occupation limits suggest 5000 ppm as 8 hour average
one thing we can offer is to validate your monitor against a calibrated standard