PPD42NS报告：http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4569398/pdf/pone.0137789.pdf 
原厂家：http://www.shinyei.co.jp/stc/optical/main_ppd42ns_e.html 
http://takingspace.org/wp-content/uploads/ShinyeiPPD42NS_Deconstruction_TracyAllen.pdf 
http://www.howmuchsnow.com/arduino/airquality/grovedust/ 
http://www3.epa.gov/airnow/teachers/gh_pmsensorkit_handoutandinstructions.pdf 

开源测试仪：http://tieba.baidu.com/p/3084818706 http://pan.baidu.com/share/link?shareid=3269736698&uk=3254806842 

http://www.elektronik.ropla.eu/pdf/stock/smy/dsm501.pdf 

R23: https://world.taobao.com/item/39271112236.htm

滤布：HV滤布测试条件下0.3um阻力Pa/通过率%，寿命5年，静电类，与HEPA机械类不同。http://world.taobao.com/item/39267801201.htm 

STC12C5410 code:http://www.chinadmd.com/search.do?nkey=dsm501%E5%BA%94%E7%94%A8