2020-026 – Low-cost Particulate Detector with Improved Accuracy

A novelcombination of three “stability point” scattering angles enables a significantincrease in accuracy and decrease of cost of environmental particulate dustsensors. Detection of light at thesethree angles allows for accurate measurement of particle size and the real andimaginary parts of the particle refractive index. Because refractive index isoften unique for most materials, it is a useful metric for in situ particle composition determination. Basedon these principles, a sensor has been developed that could monitor air qualityand environmental contaminates in a wide variety of situations including bothindoor, e.g. aircraft, buildings, etc., and outdoor, e.g. construction andagricultural sites. The sensordetermines particle size and both components of the complex index ofrefraction, giving the end-user more information about the nature of theparticulate in the air than any previous sensor that we have knowledge of. Thissystem can be used to size any type of spherical particle in a wide range ofdiameters (1–1,000 µm) with an uncertainty less than 10% for particles greaterthan 10 µm in diameter. For particles smaller than 10 µm, the uncertainty isgreater than 10% but the method still has some merit down to 1 micron. Thismethod can improve the accuracy of the size estimate obtained from low-costsensors, allowing them to compete with the uncertainty range of the moreexpensive instruments. Aarushi Gupta-Sheth aarushi@ksu.edu 785-532-3907