PurpleAir and STEM

PurpleAir and STEM

Our YCITYSCI students have learned about air pollution and how the purple air sensors we monitor around the south western Illinois area function and record air pollution data. Below are two topics that the student’s asked at the end of the air pollution session to learn more about. Our graduate research assistant, Lisa Drennen, has taken the pleasure in providing more information about the PurpleAir sensors and Dr. Black’s career for the citizen science cafe coming up soon! 

 What do the PurpleAir sensors in the local community measure?

These air pollution sensors measure particulate matter (PM) that is in the surrounding air. Particulate matter consists of  solid particles found in the air including dust, smoke, organic, and inorganic particles. The PurpleAir sensors use lasers to count the particles. The number of particles are counted and classified by size. The laser counter counts particle sizes of 0.3, 0.5, 1, 2.5, 5, and 10 m. The counted particle data is then used to calculate the mass concentrations of PM 1, PM 2.5, and PM 10. 


How do the PurpleAir sensors work?

The laser counter measures particulate matter in real time. The laser alternates readings of PM every 5 seconds averaged over 120 seconds. Each laser contains a fan that is used to draw in a sample of air through the laser beam to be counted. The beam will reflect the light from the particulates matter in the air onto a detection plate. The reflected light is measured as a pulse by the detection plate. The length of the pulse determines the size of the particulate while the number of pulses determines the number of particles in the air. 


Who uses PurpleAir sensors and data?

These sensors are used by government districts and schools. Universities use these sensors to monitor air quality inside buildings or outside areas. The sensors and data are used by individuals and groups. These sensors can be used for policy making, research, or just concerned citizens within communities. 

For more information about the PurpleAir sensors and how they work, click here

STEM Speaker for citizen science cafe

Dr. Allan Black is an assistant professor at SIUE. He graduated with his PhD from the University of Georgia in 2015. He studies climatology and meteorology. Climatology is the study of the climate. Meteorology is the study of the processes and phenomena related to the weather. Dr. Black’s research interests include atmospheric hazards, extreme climate, and their impacts on society. Dr. Black’s recent research efforts have focused on windstorms, tornado debris travel, and the impacts of inclement weather on transportation. Dr. Black is located in the department of geography and geographic information sciences at SIUE. Dr. Black was part of a tornado chase in southern, IL in December of 2018. Dr. Black has awesome photos he took of one of the 29 tornadoes that touched down in the area that day. Dr. Black watched radar and collected data to analyze the storm and where the warm front was meeting the cold front and caused the thunderstorms and tornadoes. To view the pictures of the tornado touching down in southern, IL, click here. For more information on Dr. Black and his recent research, click here.   


Photo credits:

Photo of the PurpleAir sensor found on the PurpleAir website.

Photo of Dr. Black’s website taken by Lisa Drennen from Dr. Black’s website.