Calibration of low-cost portable particulate counter (PC) to standardized-certified PC

The use of air purifier to clean the room with poor ventilation is considered as a fast and common solution to minimize the spread of SARS-CoV-2 nowadays. However, the efficacy of the filter within the air purifier must be tested priorly to ensure the cleanliness of the air, since the size of this novel virus is very small. Inexpensive particulate counter which is common in the market, such as HT-9600 particle counter can be used to test the efficacy of the filter if the device is properly calibrated. This paper aims to calibrate the HTI portable particulate counter to Solair3100 which has been calibrated by NIST using ISO 21501-4 and ISO 17025 standards. Both devices were used to measure the amount of particle in various places to see their characteristic. The same nonlinear trend produced by both devices in reading the amount of particle in different places made the calibration effort can be done. Data used for calibration were the average reading of the number of particles from various conditions. Calibration curve of HT-9600 particle counter was obtained by plotting the average readings of both devices in a single plot. The obtained calibration curve is a non-linear plot which represents the characteristic of particle counter in reading the amount of particle based on its respective size. The obtained calibration function from the curve shows great tendency in reading the right amount of particle in the air with minimum error.