In field testing, these samplers have been demonstrated to vary (CV) only 11.6% from [Federal Reference Methods](/wiki/pm-monitoring-regulations), 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. SEM Stub Monitor Documentation: * [Assembly](/wiki/passive-pm-assembly) * [Deployment](/wiki/passive-pm-deployment) * [Imaging](/wiki/passive-pm-imaging) * [Analysis](/wiki/passive-pm-analysis) 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) Citation: Darrin K. Ott, William Cyrs, Thomas M. Peters, Passive measurement of coarse particulate matter, PM10-2.5, Aerosol Science 39:156 – 167, 2008