Research of perception of textual information from explosion-proof displays by means of subjective measurements methods

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 are given. 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. Results With the results of this research the average normalized appraisal for every display was calculated for different illumination intensities. Сonclusion 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.