| 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 8 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 » | almost 9 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 » | almost 9 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 » | almost 9 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 » | almost 9 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 » | almost 9 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 » | almost 9 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 » | almost 9 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 » | almost 9 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 » | about 9 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 » | over 9 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 » | over 9 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 » | over 9 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 » | over 9 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 » | almost 10 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 » | almost 10 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 » | almost 10 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 » | almost 10 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 » | almost 10 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 » | almost 10 years ago |