Comparisons of the soot volume fraction using gravimetric and light extinction techniques

Influence of soot aggregate size and internal multiple scattering on LII signal and the absorption function variation with wavelength determined by the TEW-LII method

“…Second, application of Eq. (18) can involve extrapolation to wavelengths substantially outside the range under which the h function expressions were developed. Such extrapolation could cause error to the h function.…”

“…Nevertheless, investigations conducted so far tend to support that E(m) seems dependent on the type of fuel and the maturation of the soot particle [11][12][13]. It is well known that the soot absorption function is difficult to determine accurately and many methods have been proposed [12,[14][15][16][17][18][19][20][21][22]. Among these methods, the two excitation wavelength LII (TEW-LII) technique seeks to produce identical time-resolved and spectrally resolved LII signals by adjusting the laser pulse energy at two different laser wavelengths and permits to determine the relative spectral dependence of E(m) [1].…”

A Study on the Development of a Low-cost Device for Measuring the Optical Smoke Density

“…반면에 레 이저를 포함한 광학장치를 이용하는 광소멸법은 비교적 단 순한 구성과 실시간으로 연기밀도를 측정하는데 용이하다. 물론 광소멸법의 경우에도 연료 및 화재조건에 매우 민감 한 질량비 소멸상수(mass specific extinction coefficient) 에 대한 정보가 미리 제공되어야 하는 어려움이 있지만, 연소공학 및 화재공학 분야에서 널리 사용되고 있다 (7)(8)(9) . 화재공학 분야에서 광소멸법을 이용한 연기밀도 측정은 액체 및 고체 가연물의 연기발생량 측정 (10) , 산소소모열량 계를 이용한 열발생율 측정 (11) , 화재모델링을 위한 soot yield의 정보 제공 (12) (…”

Laser-induced incandescence calibration via gravimetric sampling

“…3,4 Light extinction is widely used for measuring these quantities but possesses limitations. 5 Interpretation of extinction measurements to determine f, or soot yields rely on assumptions and uncertainties regarding soot properties. Varying experimental conditions can affect the contributions to the extinction measurement of absorption by PAH's and scattering, hence these contributions are often neglected.…”

“…Notably, this f, does not depend upon optical properties of soot and is insensitive to scattering effects and absorption by PAH molecules. GS has recently been used in the post-flame region for determination of the fv 5 …”