Comments

Author Comment Last activity Moderation
DavidMack "It's quite a broad question to answer but when people use WebFire to estimate emissions, it's generally the best information available. Sources co..." | Read more » over 4 years ago
DavidMack "Sure, also for estimating emissions, see EPA AP-42 emission factors: https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-compilatio..." | Read more » over 4 years ago
DavidMack "You can look up the actual reported emissions from many facilities using the EPA National Emission Inventory, which is compiled every three years: ..." | Read more » over 4 years ago
DavidMack "You could probably use HD parts. It just depends on what you are sampling (corrosivity) and the threshold levels of your analysis. Ideally all "w..." | Read more » over 4 years ago
DavidMack "FEMA Journal has links to mapping: https://fema.maps.arcgis.com/apps/MapJournal/index.html?appid=97f53eb1c8724609ac6a0b1ae861f9b5 Specifically: C..." | Read more » about 7 years ago
DavidMack "http://www.emsl.com https://www.pacelabs.com " | Read more » about 7 years ago
DavidMack "it could just be a fungus among us. there are some really weird looking fungi, e.g. google "fungus that looks like vomit" and click on IMAGES. " | Read more » about 7 years ago
DavidMack "Mason jars: cheap and easily sealed. Ground glass connections are usually expensive. " | Read more » over 7 years ago
DavidMack "There are a few methods but like most scientific work it isn't always conclusive. Wind direction. A locally sited meteorological station with win..." | Read more » over 7 years ago
DavidMack "@liz see "Guidelines for FRM and FEM Applicants 9-2011 (PDF)" on https://www3.epa.gov/ttn/amtic/criteria.html " | Read more » almost 8 years ago
DavidMack "I would stick with the aluminum. It's probably the most commonly used material for PM monitoring because as you stated non-conducting materials ar..." | Read more » about 8 years ago
DavidMack "you probably also want to reference https://www.regulations.gov/ which is the federal government's one stop site for reading rule-makings and comme..." | Read more » about 8 years ago
DavidMack "neat. maybe put the fan on the charcoal side and blow into the tube so you don't get infiltration from the flap in the middle? The other way I've..." | Read more » about 8 years ago
DavidMack "one other tool you may want to consider is something like a haze cam, see http://hazecam.net/ These are typically used for wide open areas but I t..." | Read more » about 8 years ago
DavidMack "Thanks for sharing the video. That's certainly a lot of pollution. One simple thing the local community could do is document how much material is..." | Read more » almost 9 years ago
DavidMack "I was thinking you could expose the intake to ambient temperature in winter and by heating the enclosure you'd be warming the instrument and air in..." | Read more » about 9 years ago
DavidMack "@kevinvivergy great detailed post. I'm not that familiar with the Dylos--haven't handled one--but looking at some photos maybe just cut out holes ..." | Read more » about 9 years ago
DavidMack "Thanks @gretchengehrke for the update. In Balmat, J. L. "Accuracy of Formaldehyde Analysis Using the Draeger Tube," the ranges were much higher th..." | Read more » about 9 years ago
DavidMack "Excellent precision in the values for both the public lab and DOH method--so there was clearly very diligent field work! I did a quick search for ..." | Read more » about 9 years ago
DavidMack "The topic is kind of overwhelming when you think of all the possibilities but maybe one model would be to start compiling how different METHODS wer..." | Read more » about 9 years ago
DavidMack "@gpenzo the 2 ft. of chain would serve as the counter weight, then the chain would connect to a rope which is connected to an anchor. the foam dis..." | Read more » about 9 years ago
DavidMack "what if you got a solid silicone stopper and put two small needle sized holes in it (carefully) and ran each round wire through its own hole. you'..." | Read more » about 9 years ago
DavidMack "I think you just need a bigger filter or a smaller fan and it will work fine. I don't see much advantage in making an adapter plate to make these t..." | Read more » over 9 years ago
DavidMack "EPA Charles river buoy for comparison: http://www2.epa.gov/charlesriver/live-water-quality-data-lower-charles-river#LiveDataStream " | Read more » over 9 years ago