Based on the measurement data of the particulate matter with an aerodynamic diameter of less than or equal to a nominal 10 ${mu}m$ (PM10) by the ${eta}$-ray absorption method (BAM) equipped with an inlet heater and the gravimetric method (GMM) at two coastal sites in Korea, the optimal inlet heater temperature was estimated. By using a gas/particle equilibrium model, Simulating Composition of Atmospheric Particles at Equilibrium 2 (SCAPE2), water content in aerosols was estimated with varying temperature to find the optimal temperature increase to make the PM10 concentration by BAM comparable to that by GMM. It was estimated that the heated air temperature inside the BAM should be increased up to $35{sim}45^{circ}C$ at both sites. At this temperature range, evaporation of volatile aerosol components was minor. Similar ($30{sim}50^{circ}C$) temperature range was also obtained from the calculation based on the absolute humidity which changed with ambient absolute humidity and chemical composition of hygroscopic species.