Citation

Klotz RC. Transp. Res. Rec. 1976; 598: 45-46.

Copyright

(Copyright © 1976, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The evaluation of the device (constructed to measure the effective intensity (candelas), flash time (milliseconds), and period (seconds) of flashing lights in the field) consisted of a direct correlation between values obtained for the parameters measured by means of the device and optical tunnel facilities. Variables under investigation were different light manufacturers, variable light power levels, and different viewing angles. Tests showed that after careful optical alignment to a type A light powered with a voltage to cause a failing light (less than 4.0 cd at +/-9 deg horizontal, +/-5 deg vertical) the test device will read within +/-10 percent of the value currently obtainable with the optical tunnel instruments. Of the +/-0.4-cd deviation, about one-third or +/-0.12 cd can be statistically attributed to the use of regression analysis techniques; the remaining two-thirds (+/-0.28 cd) is due to measurement error, reading error, or other experimental errors. The test results justify use of the device as a laboratory testing instrument.