An Advanced Sensor for Particles in Gases Using Dynamic Light Scattering in Air as Solvent

Abstract

Dynamic Light Scattering is a technique currently used to assess the particle size and size distribution by processing the scattered light intensity. Typically, the particles to be investigated are suspended in a liquid solvent. An analysis of the particular conditions required to perform a light scattering experiment on particles in air is presented in detail, together with a simple experimental setup and the data processing procedure. The results reveal that such an experiment is possible and using the setup and the procedure, both simplified to extreme, enables the design of an advanced sensor for particles and fumes that can output the average size of the particles in air.

Profiling Particles of Sahara Dust Settled on the Ground by a Simplified Dynamic Light Scattering Procedure and Sedimentation

“…Despite being very fast, these alternatives based on ANNs do not offer any indication regarding the precision of the result, with respect to the accuracy of the monomodal approximation they are based on. An attempt to use DLS on particles in air as solvent was made, and the results are reported in [ 47 ]. However, the precision is not considerable, the main cause being the small angle and the relatively large error in measuring the angle caused by the diameter of the transparent tube containing the sample.…”

“…To overcome the uncertainty that might be generated by using an ANN-based alternative, and to overcome the possible problem of not having a sufficiently large particle concentration, a DLS time series data processing procedure that uses a fit of an analytical function to the experimental data was used in the work reported in this paper. Moreover, the procedure intended to simplify the experimental setup as much as possible and make it flexible, as reported in [ 44 , 45 , 46 , 47 ]; this is briefly presented further on. The experimental setup is presented in Figure 1 .…”

“…In (1), the a 0 parameter performs the vertical scaling of the spectrum, but a 1 depends on the diameter d of the particles in suspension, which act as scattering centers (SCs), as described by (2) [ 45 , 46 , 47 ]: …”

Impacts of Air Pollution and Dampness on Occupant Respiratory Health in Unplanned Houses: A Case Study of Bandung, Indonesia

“…Meanwhile, a digital dust meter (SIBATA, LR-5R) was also deployed to measure the TSP and PM 2.5 at 1.1 m above the floor in indoor (bedroom) and immediate outdoor environment for 24 h with an interval time of one minute (Figure 2a,c). This device applied a dust indicator based on the light scattering methods, which enabled the calculation of particles and fumes that can output the average particle size in air based on the specific sensor for particle size [55]. It is suitable for a measurement in a specific location for an extended period [56].…”

On the Possibility of Designing an Advanced Sensor with Particle Sizing Using Dynamic Light Scattering Time Series Spectral Entropy and Artificial Neural Network

“…DLS TS can be processed in a simplified manner, to produce the average diameter of the suspended particles, as in [ 7 , 8 , 9 , 10 ], or to estimate the particle size distribution, following different assumptions and approximations, as Maximum Entropy algorithms [ 11 , 12 ] or CONTIN [ 13 , 14 ]. The maximum entropy method [ 11 , 12 ] is an advanced method based on fitting.…”