ASNT Level III- Visual & Optical Testing
My Level III Self Study Notes
My Level III Self Study Notes
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1.5 Luminous Efficiency of Radiant Energy<br />
Many apparent differences in intensity between radiant energy of various<br />
wavelengths are in fact differences in the ability of various sensing devices to<br />
detect them. The reception characteristics of the human eye have been<br />
subject to extensive investigations and the results may be summarized as<br />
follows.<br />
1. The spectral response characteristic of the human eye varies between<br />
individuals, with time and with the age and health of an individual, to the<br />
extent that the selection of any individual to act as a standard observer is<br />
not scientifically feasible.<br />
2. However, from the available data, a luminous efficiency curve has been<br />
selected to represent a typical human observer. This curve may be applied<br />
mathematically to the solution of photometric problems.<br />
Charlie Chong/ Fion Zhang