The results of experimental researches of perceived textual information quality from explosion-proof luminous displays by several manufacturers in dependence of lighting
conditions, distances and sight level
Materials and methods
Testing was conducted by two methods:
the method of appraisal by points and the method of paired comparison. To conduct the testing and get results of subjective
appraisals, all the displays to be tested were fixed on 1.4 to 2.2m high stands.
An illuminometer model U116,
TU 25-04-3098-76, was used to measure
the illumination intensity of the stand with display. A total of 7 researches were
conducted for each illumination intensity
of 55000 lx, 45000 lx, 10000 lx, 5500 lx,
2000 lx, 550 lx и 300 lx at the distance of up
to 20 m and at a 60 degree solid angle.
With the results of this research the average normalized appraisal for every display was
calculated for different
If the display is intended to be used
with illumination intensity in the range
of 300 to 1000 lx, then the display
number 2 should be acknowledged
the best suitable. However, if the display
is intended to be used in the entire tested
range of illumination intensity, then, basing on the appraisals drawn from testing,
the display number 9 should be
acknowledged the best.