Smartphones as experimental tools to take measurements in environmental engineering

The thesis is focused on the measuring of the physical quantities by the means of smartphones. It gives a list of the sensors which smartphones contain and it briefly describes their function in ordinary use and their use for the measuring not only physical quantities. Sensors of the mechanical quantities are documented in a greater extent. The measurement limits are addressed as well as the information what inaccuracies of measured quantities can be expected. The study also deals with the added devices which help to overcome the limits of inbuilt sensors and by that they make the measurement more accurate. A review of several researches on already made measurements of the mechanical quantities with smartphones is also given. The last part of the study describes an experiment during which six mobile phones with Android system and six applications were tested by measuring a pink noise signal. Two main facts follows from the results. The measurement with a phone calibrated previously cannot be considered as reliable, the errors can be in the rate of tens of decibels. Whereas phones after calibration in the levels range 45 – 85 dB, when the measuring error is linear, can be used for measurement of the noise with the error less than 2 dB