Calibration of an LDR-Lux meter using a smartphone

Abstract

In this study, it is aimed to calibrate an LDR-Lux meter with a calibration setup which includes a light bulb whose brightness can be changed by using a dimmer circuit, a data acquisition card, a smartphone and a lux meter application. In order to make the measurements more accurate and to prevent errors in the measurements, a smartphone and a laptop were connected to each other via internet browser and the data obtained with physical phone experiments was displayed on the computer screen instantly. In the experimental setup, the brightness of the light was changed with the dimmer circuit and height adjustment. The data were obtained as a result of 32 experiments for different illumination values. As a result of this study, it is seen that the calibrated experimental setup works with high accuracy. With this experimental setup, it is thought that students can also easily test the inverse square law of light. The main factors that make this experimental setup effective are that, unlike other studies in the literature, a professional lux meter is not used and the cost of the developed LDR-Lux meter is very low. © 2021 IOP Publishing Ltd.