Author Affiliations
Abstract
Department of Automation Measurement and Control, Harbin Institute of Technology, Harbin 150001
In total light scattering particle sizing technique, the relationship among Sauter mean diameter D32, mean extinction efficiency Q, and particle size distribution function is studied in order to inverse the mean diameter and particle size distribution simply. We propose a method which utilizes the mean extinction efficiency ratio at only two selected wavelengths to solve D32 and then to inverse the particle size distribution associated with Q and D32. Numerical simulation results show that the particle size distribution is inversed accurately with this method, and the number of wavelengths used is reduced to the greatest extent in the measurement range. The calculation method has the advantages of simplicity and rapidness.
光全散射法 粒径分布测量 双波长法 290.2200 Extinction 120.5820 Scattering measurements 300.6360 Spectroscopy, laser Chinese Optics Letters
2007, 5(1): 31
Author Affiliations
Abstract
School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001
Clouds' radiation characteristics are very important in clouds scene simulation, weather forecasting, pattern recognition, and other fields. Radiation of a cloud mainly comes from its multiple scattering. A new algorithm to calculate multiple scattering, called build-up factor algorithm, is proposed in this paper. In this algorithm, a modified gamma distribution is assumed to describe droplets distribution inside a cloud, then the radiation transport equation is calculated to get the solution of single scattering, and finally, a build-up factor is defined to estimate the multiple scattering contributions. This algorithm considers both single scattered radiance and multiple scattered radiance and needs shorter computing time. It can be used in real time simulations.
120.0120 Instrumentation, measurement, and metrology 120.5820 Scattering measurements 290.0290 Scattering 290.4210 Multiple scattering Chinese Optics Letters
2006, 4(7): 425
Author Affiliations
Abstract
1 Department of Automation Measurement and Control, Harbin Institute of Technology, Harbin 150001
2 Department of Electronic Science and Technology, Harbin Institute of Technology, Harbin 150001
The spectral radiation characteristic of a non-luminous flame is analyzed. The apparatus and the calibration procedure based on infrared emission spectrometry for measurements of the flame are introduced. The influence of background radiation and stray light on the measurement results could be reduced and suppressed by the design of thermolator and digital lock-in technique. A blackbody cavity was used as reference emission source to calibrate the system that completed absolute measurement. The spectral measurement range is 1---20 μm. The least measuring distance and the lowest power detected at the entrance pupil are 550 mm and 10^(-9) W/cm2, respectively. The experimental results show that the measure error is less than 10%.
280.2470 flames 120.4570 optical design of instruments 300.6340 spectroscopy infrared 000.3110 instruments apparatus and components common to the sciences Chinese Optics Letters
2005, 3(9): 09549