| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| guolivar | "Short answer is NO ... longer answer is still no but with some reasons behind. In general the EPA (and any other regulatory body) needs A LOT of c..." | Read more » | over 4 years ago | |||
| guolivar | "Thanks for the heads up @liz I've been working in air quality research for 20 years and I am yet to find a reliable "low-cost" NO2 sensor. There a..." | Read more » | over 4 years ago | |||
| guolivar | "I'm sorry but as usual the time difference kills me. I could potentially listen in but at that time I cannot join the discussions (I'm too busy get..." | Read more » | almost 5 years ago | |||
| guolivar | "Normalising is your friend when you have things with very different ranges. Depending on what you're looking for you can divide each column by its ..." | Read more » | about 5 years ago | |||
| guolivar | "This is very much dataset, project and software dependent. Sometimes I remove columns, other times I combine them (averaging, adding, etc), other ..." | Read more » | about 5 years ago | |||
| guolivar | "Great tear-down! I see that a lot of love went into the Sensiron design and I mostly agree with the comments ... the issue of the HEPA filter is m..." | Read more » | over 5 years ago | |||
| guolivar | "First, I haven't used the SPS30 so can't comment on specifics for those sensors. However, I have many years of experience working with aerosol meas..." | Read more » | over 5 years ago | |||
| guolivar | " The particle size distribution (mass, volume or number) is very variable and even though "on average" it's fairly stable, the day-to-day variabili..." | Read more » | over 5 years ago | |||
| guolivar | "Short answer ... No. Long answer ... Absolutely no! I'll try to explain why, even though it sounds possible, the uncertainties are so large that t..." | Read more » | over 5 years ago | |||
| guolivar | " Quickly to your question of: For example, the first 6 are two sets of PM1, PM2.5, and PM10 concentrations. the first set are labeled "standard", w..." | Read more » | over 5 years ago | |||
| guolivar | " All the way in New Zealand we also use Gradko for all our passive tubes needs. " | Read more » | almost 6 years ago | |||
| guolivar | " It all depends on what your objectives are. You'll notice that most air quality monitoring stations (the regulatory ones) have wind measurements w..." | Read more » | almost 6 years ago | |||
| guolivar | "Following on @jeffalk answer, please expand on your question. In my opinion (and I've worked in aerosol science for a number of years) the main poi..." | Read more » | about 6 years ago | |||
| guolivar | "As far as I know Plantower hasn't disclosed that (to be fair, I don't think any of the low-cost manufacturers has done either). From the field test..." | Read more » | about 6 years ago | |||
| guolivar | "Here is a page about the PMS5003 and 7003 ... https://aqicn.org/sensor/pms5003-7003/ The difference seems to be in their internal layout. In that ..." | Read more » | about 6 years ago | |||
| guolivar | "I'll try to unpack a couple of things here. The use of zero filters is standard practice as a quick check of particle instruments. It is used to t..." | Read more » | over 6 years ago | |||
| guolivar | "I'm sorry, this got buried in my inbox ... I don't even remember seeing a notification about the original question! The short answer is that I don'..." | Read more » | over 6 years ago | |||
| guolivar | "Great work @sagarpreet! This might get rambly because there is no right answer but I'll try to explain why and what then. The first thing you nee..." | Read more » | over 6 years ago | |||
| guolivar | "The description of the operating principle can be misleading. Optical particle measurements rely on intensity of scattering rather than "amount of..." | Read more » | almost 7 years ago | |||
| guolivar | "Some colleagues from Australia have been working on AirRater (https://airrater.org/) and we're working towards adapting it for specific projects. I..." | Read more » | almost 7 years ago | |||
| guolivar | "I tried to put a long answer here but it kept throwing errors so I wrote a note with my thoughts on this issue: https://publiclab.org/notes/guoliv..." | Read more » | almost 7 years ago | |||
| guolivar | "Smoke particles (and by smoke I mean combustion products) come in sizes all the way down to 1nm (0.001micron) and in shapes that make it very trick..." | Read more » | over 7 years ago | |||
| guolivar | "You're right, the effect of humidity would be to change the "apparent" size but it's not just increasing the number of particles that now fall in t..." | Read more » | over 7 years ago | |||
| guolivar | "Yes, environmental conditions do affect the ability of an optical sensor, not too much to "see" a particle but rather to "size" it. All of these o..." | Read more » | over 7 years ago |