Transmitted light intensity

Contrast. This can be quantified as the ratio of transmitted light intensity in the bright state compared to the dar... 

It = intensity of unscattered transmitted light intensity of incident light... 

Figure 1.1 Optical arrangement for a photochemical reaction by a collimated beam of radiation of cross-sectional area A. LS=light source, L=lens, F=filter, S=collimating shield, C= reaction cell, ( optical path length, Io=incident light intensity, 1—transmitted light intensity.

Knowing that 7a = 70 — 7t (/t represents the transmitted light intensity), equation (12.2) relates If to the concentration C of the compound as follows ... 

Diverse instruments employing the principle of this experiment are used to measure mercury, a toxic and volatile element, present in many work areas. A device has been designed as a colorimeter dedicated for this single element. The source is a mercury vapour lamp and the cell is a transparent tube filled with the atmosphere to be monitored. If mercury vapours are present in the optical path, absorption of radiation emitted by the lamp will occur and this will lead to a decrease in the transmitted light intensity measured by the instrument. 

Sensitivity is defined as the concentration of the element, in fig/ml, which will lead to a l % decrease (A = 0.0044) in the transmitted light intensity of an aqueous solution. Calibration curves should be in the range of 20 to 200 times this limit. 

Fig. 9a, b. Transmitted light intensity through the thin film gels is plotted as a function of illuminated light intensity at fixed temperatures, (a) 1BIS6CH, (b) 1BIS10CH... 

Schematic diagram of a spectrophotometer for measuring light absorption. Laboratory instruments for making measurements are much more complex than this, but they all contain the same basic components a light source, a monochromator, a sample, and a detector. A is the wavelength of the light, /0 and I are the incident light intensity and the transmitted light intensity, respectively, and d is the thickness of the absorbing solution.

Fig. 2. Absorption spectrum of oxygen in the Schumann-Runge band system. The absorption coefficient, k, is defined by the equation I = la exp ( — kx), where h and I are the incident and transmitted light intensities and x is the layer thickness of the absorbing gas reduced to STP. This figure is taken from ref. (101) with the permission of The Journal of Chemical Physics.

Hz was detected in the transmitted light intensity Ij at wavelength 514.5 nm. The characteristic relaxation time rr of the DCMS measured in experiment was order of 2 ms, thus meeting the assumption that Q, o-... 

In the presence of humic material, the transmitted light intensity available for absorption for wavelength of 254 nm by H2Oz after traveling a distance of x cm can be expressed as follows ... 

Nonlinear transmission (NLT) measurements have frequently been used for single wavelength measurements (although some studies have exploited frequency-dependent NLT, for example, see Ref. [20]) here a transmitted light intensity, It, is simply measured as a function of incident light intensity, I0. In the case... 

There are several techniques available to measure the optical absorption in a-Si H. Optical transmission and reflectivity, and ellipsometry measure the high energy, high absorption transitions. In the weak absorption regime near the band edge, the measurement is made difficult by the limitation on sample thickness to a few microns. The transmitted light intensity, T, through a sample is approximately. 

Fig. 5. Plots of A, transmitted light intensity and B scattered light intensity (arbitrary units) against temperature for an initially homogeneous blend of an ethylene vinyl acetate copolymer with a chlorinated polyethylene. At the phase separation temperature there is a drop in transmitted intensity and a rise in scattered intensity...

Optical penetration depth the distance into the semiconductor at which the transmitted light intensity reaches 1/e of the incident light intensity at the surface of the semiconductor... 

A related, useful quantify for characterizing the absorption of light by semiconductors is the optical penetration depth (Figme 5). This quantity is defined as the inverse of the absorption coefficient that is, penetration depth s. From equation (4), it can be seen that the penetration depth is the distance into the semiconductor at which the transmitted light intensity reaches 1/e of the incident light intensity at the smface of the solid. In general, when compared to direct... 

---