Abstract: The invention relates to a method and device for simultaneously measuring mass concentrations of particulates with different sizes. The method detects particulates within different size ranges in air based on laser scattering and can eliminate cross interference between the particulates within different size ranges. The device is simple in structure, can realize on-line simultaneous measurement of PM1.0, PM2.5 and PM10 with high measurement precision and low cost.

Abstract: An ultrasonic gas sensor includes a housing, and a first ultrasonic transducer and a second ultrasonic transducer that are separately arranged at a top of an inner chamber of the housing, where the first ultrasonic transducer and the second ultrasonic transducer form a V-shaped ultrasonic transmission path in the housing; the housing is provided therein with a gas inlet channel and a gas outlet channel; an upper end of the gas inlet channel is close to the first ultrasonic transducer, and an upper end of the gas outlet channel is close to the second ultrasonic transducer, such that a measured gas flow entering a bypass tube passes through a detection area of the first ultrasonic transducer and the second ultrasonic transducer; a lower end of the gas inlet channel and a lower end of the gas outlet channel communicate with a gas sensor mount.

Abstract: The invention relates to a method and device for simultaneously measuring mass concentrations of particulates with different sizes. The method detects particulates within different size ranges in air based on laser scattering and can eliminate cross interference between the particulates within different size ranges. The device is simple in structure, can realize on-line simultaneous measurement of PM1.0, PM2.5 and PM10 with high measurement precision and low cost.