(주)에이피엠엔지니어링

광산란 방식 간이형 미세먼지 센서의 입경 분리능 평가기법 개발

Development of Particle Size Resolution Evaluation Method of OPC-type Low-cost and Mid-to-low cost Dust Sensors

Abstract

Low-cost dust sensors are widely used because of their advantages in real-time measurement, portability, and low price. Low-cost dust sensor which adopts the OPC (optical particle counting) method converts the intensity of light scattering into an 

electrical signal to measure the particle size. It provides mass concentration information of dust to consumers through its 

own algorithm using the measured particle size information. However, most manufacturers do not provide information on

the sensor’s size segregated mass concentration calculation algorithm, therefore users cannot know whether the sensor 

accurately measures the particle size or not. In this study, the particle size resolution performance evaluation of four types of 

low-cost dust sensors and one type of mid-to-low-cost type dust sensor, most commonly used in the market, was performed.

Test particles were aerosolized and injected into a chamber and simultaneously measured with low-cost dust sensors and a 

reference measuring device (aerodynamic particle sizer; APS). The sensor’s electrical signals obtained through communication

were correlated with the particle sizes measured by APS. As a result, it was confirmed that the four types of the low-cost 

dust sensors could not segregate the size of particles. Thus, the mass concentrations provided by the four types of the low-

cost dust sensors and APS did not match each other. On the other hand, the mid-to-low-cost dust sensor could segregate

the size of particles. Therefore, the mass concentrations measured by the mid-to-low-cost dust sensor and the mass

concentrations measured by APS were similar to each other. The performance evaluation method that simply compares the

mass concentration provided by a standard measuring instrument (beta ray measurement method, gravimetric method) and

the mass concentration provided by low-cost dust sensor is not traceable. Therefore, it is important in terms of traceability

to evaluate whether the low-cost dust sensors segregate the size of particles by light scattering method. 

Key words 

Low-cost dust sensor, Optical particle counter (OPC), Particle size resolution, Mass concentration