Using a Mobile Phone as a Measurement Tool for Illuminance in Physics Education

Abstract

Most primary school students in the Czech Republic have a mobile phone. A mobile phone can measure many physical quantities once the appropriate application has been installed. The terms “Light Meter” or “Lux Meter” are names for applications that measure the physical quantity illuminance. At the time of writing, there are more than 50 such applications available on Google Play. These applications utilise data from the ambient light sensor. The study describes the measurement of illuminance using laboratory equipment and mobile phones with installed applications and further explores the reliability of data collected by mobile phones. A comparison was made between data from applications that were in the default settings and calibrated. The values of different applications installed on the same mobile phone were compared, as well as values of the same application installed on different mobile phones. Values were compared at different distances from the light source and at the same distance, but with varying angles. The reaction time for a mobile phone application to detect changes in illumination was measured. Sensitivity to infrared and ultraviolet radiation was also investigated. Seven general conclusions were drawn from all measurements regarding the use of a mobile phone as a luxmeter instead of professional laboratory equipment, provided that the recommendations are followed.