Comments

Author Comment Last activity Moderation
DavidMack "first thing that comes to mind is a beer ball--do they even make those anymore? also look at "floating pool lights" Maybe you can get them wholes..." | Read more » over 5 years ago
DavidMack "That's great work. The videos are very well done and have a lot of info explained in a nice, straight forward manor. I like the photo card. Add ..." | Read more » over 5 years ago
DavidMack "Kudos all around for a great site! I love the Notes and feel guilty I'm in the 80th percentile of lurkers--will have to post something. Wiki page..." | Read more » over 5 years ago
DavidMack "formaldehyde info from the Agency for Toxic Substance Disease Registry (ATSDR) http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=39#12 S..." | Read more » over 5 years ago
DavidMack "Looks nice. I had an idea for an alternate gas volume measurement technique whereby you connect the exhaust side of the pump to a deflated bag the..." | Read more » over 5 years ago
DavidMack "@mathew Great work and the title is appropriate! Sometimes when I’d compare instruments head to head it would be referred to a “shoot out”—an inst..." | Read more » over 5 years ago
DavidMack "@mathew I believe you have the VWR series FR2000 rotameter, which the accuracy is specified as +/- 5% of full scale, so that's +/- 0.05 lpm. see h..." | Read more » over 5 years ago
DavidMack "I think the rotameter is going to be easier to use than the critical orifice/differential pressure method, especially with a fluid manometer. You ..." | Read more » over 5 years ago
DavidMack "Looks like a nice setup! For bubbles, the cheap ready made option would be any liquid bubble--the kid's toy to blow bubbles. @danbeavers I think ..." | Read more » over 5 years ago
DavidMack "Are there any DustDuinos or Shenyei PPD42NS sensors out there running long term? It would be interesting to see how they correlate to the EPA refe..." | Read more » almost 6 years ago
DavidMack "PVC pipe works well. What are you using exactly--can you post a photo? For PVC, you can choose whatever diameter pipe you need then glue a cap on..." | Read more » about 6 years ago
DavidMack "The commercial air flow meters are easy to use and come with NIST traceable certificates but you can make your own air flow meter for lab use that ..." | Read more » about 6 years ago
DavidMack "Here's one of the EPA source sampling methods: select method 316 in the pick list here for the purified DI water capture method: http://www.epa.gov..." | Read more » about 6 years ago
DavidMack "It sounds like a novel approach to breakdown formaldehyde. However, if you're in a situation whereby outdoor air is cleaner than indoor air, would..." | Read more » about 6 years ago
DavidMack "seems like a good approach. maybe specify the type of salt: fine sea salt, table salt (with iodine), kosher salt (no iodine), or Himalayan pink sa..." | Read more » over 6 years ago
DavidMack "@jefffalk TSI explains the instrument and its calibration in documents on its web site: http://www.tsi.com/DUSTTRAK-Aerosol-Monitor-8520/ see "th..." | Read more » over 6 years ago
DavidMack "@amysoyka The Powermag graphic portrays the PM fractions based on source sampling techniques used for power plant emission sampling. The source sa..." | Read more » over 6 years ago
DavidMack "sorry for the late reply but as you probably discovered as the air sample relative humidity increases, the moisture increasingly interferes with th..." | Read more » over 6 years ago
DavidMack "Okay, I read the research paper and the heat convection air flow dependent on the sensor orientation. I also found this report which describes the..." | Read more » over 6 years ago
DavidMack "I'd say the heater/resistor is used to heat the air sample to avoid condensation in the chamber and on the optics. Also, any aerosol (liquid and s..." | Read more » over 6 years ago