True profile-measuring devices

Overall, the advantages of the Dipstick and walking profiles are that they are lower-cost devices, easy to operate and accurate (Class 1 resolution ASTM E 950), and can be used to calibrate other profile devices. However, they are not ideal for measuring long lengths. 

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The measured peak absorption coefficient, Kmax, for a discrete impurity transition depends on the oscillator strength of the transition and on the impurity concentration. The measured profile of a recorded line is the convolution product of its true profile by the instrumental function of the spectroscopic device used. It depends significantly on the ratio of the true FWHM of the line to the spectral resolution (the spectral band width) of the spectroscopic device. When this ratio is of the order of 3 or above, the measured FWHM can be considered as the true FWHM and the observed profile is close to the true profile. For lower values of this ratio, the measured FWHM increases steadily while the measured value of Kmax decreases, and it is assumed that when the ratio becomes l/3 or smaller, the measured FWHM is the spectral resolution and the measured profile the instrumental function. This effect is known as instrumental broadening. For isolated lines, the absorption coefficient can be integrated over the entire line to give an integrated absorption I A ... 

Measure the true surface profile of the pavement. Reference elevation is the instrument height or position. Roughness is determined in the fundamental index IRI. Typical devices rod and level. Dipstick and walking profiler. 

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