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Passive Particle Monitoring
passive-pm

###Introduction A passive particle monitor measures particles without the use of mechanical or electrical systems, depending instead on natural wind-blown deposition of particles on a collection surface. Passive particle monitoring is frequently used for qualitative "nuisance dust" measurements, and more recently to extrapolate [airborne PM concentrations](https://publiclab.org/wiki/pm) and the direction dust comes from. Passive monitoring promises to be less expensive and more robust than active monitors' mechanical and electrical components, but comes with a different set of challenges. Public Lab is investigating one [promising passive monitor](/wiki/sem-stub-pm) as a tool for measuring airborne PM concentrations. [Read more in Public Lab PM tool development.](/wiki/pm-dev) ###Advantages and Disadvantages **Advantages** | **Disadvantages** --------------------|--------------------- low cost (less than $100 devices) | deployed for 3-7 days, low temporal resolution deployed without electricity | not real-time (results must be analyzed after collection) simple setup and calibration | analysis can be labor intensive or expensive actual particles are collected | particle speciation is limited by method and cost can generate airborne particle concentrations | no way to extrapolate to airborne concentrations of speciated particles may correlate well with [Federal Reference Methods](https://publiclab.org/wiki/pm-monitoring-regulations#The+Federal+Reference+Methods:) | not an officially recognized method electret methods are particle-specific | electret methods are particle-specific ###Devices ####[SEM Stub Monitors](/wiki/SEM-stub-pm) In field testing, these samplers have been demonstrated to vary (CV) only 11.6% from [Federal Reference Methods](https://publiclab.org/wiki/pm-monitoring-regulations#The+Federal+Reference+Methods:), when measuring course particulates (PM10-2.5), making this the most precise published passive particle monitor design (Ott, Cyrs, & Peters, 2008). Public Lab is evaluating the deployment of this technology. [Read More](/wiki/SEM-stub-pm) Developed originally for indoor dust monitoring at the University of North Carolina by Jeff Wagner and David Leith, this tiny monitor (in the middle of the housing, below) consists of a fine mesh cap over top of a Scanning Electron Microscopy (SEM) pin stub, a small aluminum object that looks like a pin. Thomas Peters and Darrin Ott at the University of Iowa added a wind-and-rain housing so the monitors can be used outside. They also added a glass microscope slide cover on top of the stub, allowing lower-cost analysis with a standard visible-light microscope. [![Amber Wise removing a stub cover](//i.publiclab.org/system/images/photos/000/012/171/original/IMG_20151020_175427.jpg)](//i.publiclab.org/system/images/photos/000/012/171/original/IMG_20151020_175427.jpg) [![IMG_20151015_120027-trim.png](//i.publiclab.org/system/images/photos/000/013/521/medium/IMG_20151015_120027-trim.png)](//i.publiclab.org/system/images/photos/000/013/521/original/IMG_20151015_120027-trim.png) Analysis is performed in [ImageJ](http://fiji.sc/Fiji). roughly: [![Analysis Steps](//i.publiclab.org/system/images/photos/000/011/635/original/imagejsteps.jpg)](//i.publiclab.org/system/images/photos/000/011/635/original/imagejsteps.jpg) [Read More](/wiki/SEM-stub-pm) Citation: Darrin K. Ott, William Cyrs, Thomas M. Peters, Passive measurement of coarse particulate matter, PM10-2.5, Aerosol Science 39:156 – 167, 2008 ###Sticky Pad Monitors Developed to track 'nuisance dust,'(i.e. any visible dust blowing onto properties adjacent from a dust producing industrial operation), sticky pads are pieces of tape that collect wind-blown dust. No system for speciating particles or correlating particle accumulations with airborne concentrations has been developed, however, sticky pads are the only dust monitoring system that records the direction dust came from. The most advanced system, developed at the University of Leeds and spun off into the [DustScan](http://www.dustscan.co.uk/) company, uses two sticky pads-- a cylindrical pad used to track the direction dust comes from, and an upward-facing sticky pad to track total dust. The devices are made from standard sizes of ABS drainage pipe and commercially available tape. [![DustScan Sticky Pads](//i.publiclab.org/system/images/photos/000/004/526/original/Screen_Shot_2014-06-04_at_8.20.00_PM.png)](//i.publiclab.org/system/images/photos/000/004/526/original/Screen_Shot_2014-06-04_at_8.20.00_PM.png) For analysis, sticky pads are scanned at low resolution, and the relative darkness or lightness (albedo) is measured by software to quantify dust accumulation. [Read More](/notes/mathew/06-05-2014/the-development-of-stickypad-monitoring) ###Other Passive Monitors ####Vinzents Passive monitor A small dual-sticky pad system designed for indoor use only, with one pad facing up and the other one horizontal. This system uses a similar deposition model as SEM stub monitors, and analysis can be performed using optical microscopy. See: Vinzents, PS. A Passive Personal Dust Monitor. Annals of Occupational Hygiene, 40: 261-80, 1996. Schneider et al. Passive Sampler Used for Simultaneous Measurement of Breathing Zone Size Distribution, Inhalable Dust Concentration and other Size Fractions Involving Large Particles, Annals of Occupational Hygiene, 46:187-195, 2002. ####Exposed Filter Systems ####Ferm Passive Monitor Martin Ferm has developed two different monitors: 1) a series of vertical strings less than 1mm in diameter collect particles from all directions for analysis with mass spectrometry, not investigated because of the expense of analysis. 2) a polypropylene container with an exposed filter, for mass spectrometry. See: Fern, Martin, Development and Test of a Passive Sampler for Fine Particles, Swedish Environmental Research Institute, 2010. ####Einstein–Lioy Deposition Sampler A similar arrangement to the Ferm monitor, with four exposed 37mm filters for mass spectrometry analysis. See: Einstein et al, Design and Validation of a Passive Deposition Sampler, Journal of Environ Monitoring 2012 September ; 14(9): 2411–2420 ####Brown Electret Sampler A system with an 'electret,' or semi-permanent charged material, filter. Requires expensive analytical chemistry methods. See: Brown, R. C., Hemingway, M. A., Wake, D., and Thompson, J. . Field Trials of an Electret-Based Passive Dust Sampler in Metal Processing Industries, Ann. Occup. Hyg. 39:603– 622. 1995 ####Personal Aeroallergen Sampler (PAAS) Unknown operation, couldn't get the article. Support open science. Yamamoto et al. A passive sampler for airborne coarse particles Journal of Aerosol Science Volume 37, Issue 11, November 2006, Pages 1442–1454...


Author Comment Last activity Moderation
mathew "the paper is a great substrate! cool exercise. " | Read more » over 4 years ago
liz "Sent in my a community member, here's a classroom example from 1991 for an activity to make sticky pads, install them around their school yard, ana..." | Read more » over 4 years ago
Matej "Amazing!! Thank you @warren and @matthew!! All very helpful! My bigest concern was where to get the mesh with correct hole diameter. The github is ..." | Read more » over 4 years ago
mathew "@Matej the most up-to-date information and production files are in the Github repository: https://github.com/publiclab/passive-pm The screen and m..." | Read more » over 4 years ago
warren "Hi, @matej - check out this for ways to sort particles by size using an "impactor" - https://publiclab.org/wiki/filter-pm SEM stub info: https://p..." | Read more » over 4 years ago
Matej "Hey @matthew! I am trying to build same PPM kit you guys have here. Where did you guys get the sampler stub? I understand that it is the electron m..." | Read more » over 4 years ago
stevie "Hi @SimonPyle hope all is well! Wanted to connect you to @tech4gt who is working on a process like this for microscope slide images. Here's a post ..." | Read more » over 4 years ago
warren "@emmyallyn -- that's a great question which I think we will want to dig deeper into as we make progress on analyzing microscopic photos of dust (se..." | Read more » over 4 years ago
emmyallyn "Just wondering, how did you confirm that the particles that illuminate are silica? Lots of different minerals (based on their anisotropic nature) s..." | Read more » over 4 years ago
amirberAgain "Saw this during the air pollution open call today, It looks really nice! any reason you used ImageJ and not Python + OpenCV? " | Read more » over 4 years ago
amirberAgain "I think they already had a very similar previous publication, but this came up today in one of my Scholar alerts: https://pdfs.semanticscholar.org/..." | Read more » over 4 years ago
amirberAgain ":) OK, Got that now! " | Read more » over 4 years ago
stevie "Ah yes - but good question! There is also an OpenHour tonight at 8pm on Hydrogen Sulfide Monitoring Methods which should be great as well. The par..." | Read more » over 4 years ago
amirberAgain "@stevie any chance you meant to 8pm and not 2pm? https://groups.google.com/forum/#!topic/publiclaboratory/1wnDDulduXs " | Read more » over 4 years ago
amirberAgain "Will try to! " | Read more » over 4 years ago
stevie "Hi there! We're going to be chatting about this on the OpenCall tomorrow at 2pm Central if you're interested in joining on! https://publiclab.org/w..." | Read more » over 4 years ago
amirberAgain "What could be applicable here is a lens free holographic microscope. I've been wanting to build one for a long time, maybe this will be my excuse! ..." | Read more » over 4 years ago
squattingdog "Thanks @warren and @richardbowman for replying, it's appreciated. I'm quite familiar with microscopes and macro photography. I have a Nikon Optipho..." | Read more » over 4 years ago
warren "Indeed -- we're hoping the basic microscope kit will create an influx of folks who go on to make openFlexure microscopes! " | Read more » over 4 years ago
richardbowman "Hi @squattingdog, just thought I'd pop up and say that the openflexure microscope is still very much under active development - I've improved my bu..." | Read more » over 4 years ago
warren "Hi, @squattingdog - we've been working on an "introductory" microscope build that's an easier stepping stone to this one, which you can upgrade lat..." | Read more » over 4 years ago
squattingdog "@mathew any progress on this build? I was interested in giving it a shot myself but wasn't sure where to start since I've seen very little activity..." | Read more » over 4 years ago
AdditiveFutures "stacked acrylic sheets. volumes determined through cutting thin sheets with a laser cutter.. " | Read more » over 4 years ago
stevie "Hi there! This wiki page has a lot of information on it about the differences between passive and optical particulate matter monitors. https://publ..." | Read more » over 4 years ago