Device and method for rapidly measuring water content of nanoscale particles

Abstract

The invention relates to a device and a method for rapidly measuring the water content of nanoscale particles. The device comprises a clean humid air generation unit, a particulate matter humidity exchange unit, a nanoscale particulate matter number concentration spectrum distribution measurement unit and a dynamic PID humidity feedback adjustment unit. The clean humid air generating unit comprises an air source, a Nafion humidifying pipe, a Nafion drying pipe and a three-way electromagnetic valve. The nanoscale particle number concentration spectrum distribution measurement unit comprises a differential electromigration analyzer and a particle number concentration detector. The dynamic PID humidity feedback adjusting unit comprises a first humidity sensor, a second humidity sensor, a third humidity sensor, an ambient atmospheric humidity sensor, a two-way selector, a subtracter, an adder, a PID controller and a pulse width modulation driver. The invention can significantly improve theprecision and time resolution of particulate matter water content measurement, can be applied to online measurement and real-time inversion of ambient air nanoscale (3-100 nm) particulate matter water content, and the time resolution is superior to 10 minutes.

Description

technical field [0001] The invention relates to the technical field of aerosol analysis and monitoring, in particular to a device for quickly measuring the water content of nanoscale particles and a measuring method thereof. Background technique [0002] Atmospheric nanoscale particles interact with water vapor to increase the water content of particulate matter, which affects the formation, growth and heterogeneous chemical reactions of atmospheric nanoscale particles, and has direct and indirect effects on atmospheric visibility and cloud climate effects. It belongs to the research field of particulate matter. one of the fundamental issues. The atmospheric lifetime of nanoscale particles is short, and their physical and chemical properties are unstable, resulting in rapid changes in the number concentration spectrum distribution of nanoscale particles in the ambient atmosphere. Moreover, the charging efficiency of particles below 100nm in the atmosphere is low, and the di...

AI Technical Summary

Problems solved by technology

The atmospheric lifetime of nanoscale particles is short and their physical and chemical properties are unstable, resulting in rapid changes in the number concentration spectrum distribution of nanoscale particles in the ambient atmosphere

Moreover, the charging efficiency of particles below 100nm in the atmosphere is low, and the diffusion loss is significant, which increases the difficulty of online measurement of the water content of nano-scale particles

At present, the existing method directly samples and measures the ambient air. For example, Chinese patent CN 105203434A discloses a particle size spectrometer for

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