This article presents the results of a research study focusing on the effect of tilt angle changes on the power balance of photovoltaic (PV) systems. The objective of this study was to determine tilt-angle-induced differences in the power balance of two different types of photovoltaic modules: bifacial and monofacial. A comparison of the power balance results, obtained for the PV modules installed on the roof a building with tilt angles of 25° and 90°, was made. Ultimately, the simulation of power changes was performed for the modules installed on the roof with different black and white surfaces. The measurement data were collected using the solar invertors FRONIUS IG and the pyranometer CMP 11. The results obtained indicate that the PV system integrated into the building's façade had a better power balance than the PV system installed on the building's roof in the period from October to January. The power of the bifacial PV modules considered was found to be greater than that of the monofacial PV modules considered. The energy production of bifacial modules proved greatly dependent on the roof surface reflection coefficient.

This paper deals with the determination of the absolute errors of a small time of flight (ToF) distance sensor with respect to coloured surfaces at different illumination intensities. The aim was to determine the absolute error of the measured distance by the VL53L1X sensor when set to short-mode and long-mode at different illumination intensities: 10 lx and 350 lx depending on the coloured surface using regression analysis methods. The research was performed using 7 colour samples with different spectral colours determined according to the CIE Lab colour model. Based on the performed experiments, it was found that the error at different sensor settings, change of colour surface and different illumination intensity is approximated by a linear function only up to a certain measured distance. The process is influenced by proposed factors such as: illumination intensity, coloured surface with different illumination reflectance and signal-noise parameters of the tested sensor during the experiment.

The paper presents the designed system to measurements of gas sensor transient characteristics. Electrochemical oxygen sensor SK-25F was selected for measurements from point of view application in health care and ensuring human safety in industrial production facilities and laboratories. The aim of this work is to design an automatic system for measuring the transient function G(s) of electrochemical sensors and to identify the mathematic model from a sample of sensors. The automatic measurement system based on a microcontroller for the measurements of dynamical characteristics of gas sensors was designed and developed. The result is transfer function with fit to estimation data higher as 99.48 %. The bandwidth of gas sensors was calculated on average at 0.0285763 Hz with a maximum deviation of 0.34 %. Finally, an algorithm for detecting the exceeding of the frequency range of an electrochemical gas sensor is proposed. Its application is in speed control UAV with the aim of accurate measurements of gases in the air by electrochemical sensors.INDEX TERMS sensors, oxygen, measurement techniques, transfer functions, electrochemical devices, Laplace equations.

At present, there are several types of propellers in the field of the use of Unmanned Aerial Vehicles (UAVs) with unknown parameters, where it is necessary to provide information about their thrust, current consumption and maximal rotational speed (RPM). Commonly used methods for measurement of a propeller's thrust are mostly based on the usage of a single purpose system, on short measurements without data storage or on inaccurate sensors. The goal of this article is to develop a universal experimental measuring system for more accurate measurement of propeller's parameters (thrust, current consumption, maximal RPM). For more accurate measurement, the battery voltage, temperature and humidity of the environment were also measured. To acquire, measure and store the data safely on a micro SD card, a processing circuit based on an ATmega2560 microcontroller was developed. This innovative approach allowed to analyse the behaviour of the propeller and to measure the dependencies of the RPM on pulse width, of the current on RPM and of the thrust on RPM at different input conditions. The measurements have shown that the dependencies can be approximated by cubic functions. The mathematical description allows predicting the behaviour of the propeller in unmeasurable conditions.