This article deals with the possibility of using alternative energy sources for power of biomedical sensors with low power consumption, especially using the Peltier effect sources. Energy for powering of the target device has been used from the available renewable photovoltaic effect. The work is using of "energy harvesting" or "harvest energy" produced by autonomous generator harvesting accumulate energy. It allows to start working from 0.25 V. Measuring chain consists of further circuit which is a digital monitoring device for monitoring a voltage, current and power with I<sup>2</sup>C bus interface. Using the Peltier effect was first tested in a thermocontainer with water when the water heating occurred on the basis of different temperature differential between the cold and hot side of the Peltier element result in the production of energy. Realized prototype was also experimentally tested on human skin, specifically on the back, both in idle mode and under load.
This paper concerns the issues of construction and experimental tests of a temperature stabilization system for small resistance increments measurement circuits. After switching the system on, a PCB board heats up and the long-term temperature drift altered the measurement result. The aim of this work is reducing the time of achieving constant nominal temperature by the measurement system, which would enable decreasing the time of measurements in the steady state. Moreover, the influence of temperatures higher than the nominal on the measurement results and the obtained heating curve were tested. During the working process, the circuit heats up to about 32 °C spontaneously, and it has the time to reach steady state of about 1200 s. Implementing a USART terminal on the PC and an NI USB-6341 data acquisition card makes recording the data (concerning temperature and resistance) in the digital form and its further processing easier. It also enables changing the quantity of the regulator settings. This paper presents sample results of measurements for several temperature values and the characteristics of the temperature and resistance changes in time as well as their comparison with the output values. The object identification is accomplished due to the Ziegler-Nichols method. The algorithm of determining the step characteristics parameters and examples of computations of the regulator settings are included together with example characteristics of the object regulation.
This paper concerns the experimental determination of the emissivity of selected materials (metals and alloys). In the first chapter the theoretical aspects are presented. Then ISO 18434-1:2008 norm, as the standard regulating all issues related to the emissivity and the way of its determination, is described. The aim of work was to modernize the laboratory stand for non-contact temperature measurements. The modernized laboratory stand was equipped with the modern data acquisition module (National Instruments NI 9203). It enabled to present temperature measurement data and to save it on the PC. As a result, students will be able to conduct more measurements and to make more conclusions about the emissivity of materials and its influence on a temperature result. Sample measurements and calculations were presented. The final element of study was to determine emissivity for each plate. It was made by calculations basing on the values: reference temperature (from Pt100 sensor) and non-contact temperature (from pyrometer). The emissivity values determined from these calculations were compared with the values obtained through published tables in the literature and with the values received by means of NEC Avio G100 thermographic camera. The expanded uncertainty of determined emissivity coefficient was also estimated.
The aim of this work was to make a monitoring dedicated to an off-grid installation. A laboratory set, which was built for that purpose, was equipped with a PV panel, a battery, a charge controller and a load. Additionally, to monitor electrical parameters from this installation there were used: LabJack module (data acquisition card), measuring module (self-built) and a computer with a program, which allows to measure and present the off-grid installation parameters. The program was made in G language using LabVIEW software. The designed system enables analyzing the currents and voltages of PV panel, battery and load. It makes also possible to visualize them on charts and to make reports from registered data. The monitoring system was also verified by a laboratory test and in real conditions. The results of this verification are also presented.
This article present the results of research concerning the analysis of the possibilities of applying a PGA309 integrated circuit in transducers used for pressure measurement. The experiments were done with the use of a PGA309EVM-USB evaluation circuit with a BD|SENSORS pressure sensor. A specially prepared MATLAB script was used in the process of the calibration setting choice and the results analysis. The article discusses the worked out algorithm that processes the measurement results, i.e. the algorithm which calculates the desired gain and the offset adjustment voltage of the transducer measurement bridge in relation to the input signal range of the integrated circuit and the temperature of the environment (temperature compensation). The checking procedure was conducted in a measurement laboratory and the obtained result were analyzed and discussed.
The present article contains methods determining of the gravitational acceleration components in the measurement signal of accelerometers. Eliminating those unwanted values of the MEMS sensors signals enables recording actual accelerations affecting an object. Only a signal transformed in this way can be used in order to estimate the object location or construct the inertial navigation systems. The theoretical part of the work presents methods of the orientation representation with the use of Euler angles and quaternions. An algorithm of quaternion formation with the use of the rotation angles and a direct method using the accelerometer measurement data in the vector form are also presented here. The theoretical description of three algorithms of the gravitational acceleration components elimination, in which the universal method used at the changeable object orientation in movement and methods used at constant orientation, are described. One of the presented algorithms exploited the global gravity vector transformation into a local system with the use of the Direct Cosine Matrix and quaternions. Other described algorithms were based on eliminating the constant value by applying a digital filter and appropriate algebraic transformations.
In this article a laboratory stand for measuring the impact of temperature on the electrical parameters of a photovoltaic panel is presented. For this purpose, the original program in LabVIEW for temperature, electric current and voltage acquisition in real time had to be created. Data acquisition was done automatically. On the basis of the results, the current-voltage characteristics were created. Moreover, the temperature coefficients and efficiency of a photovoltaic panel were calculated. The parameter values of a polycrystalline photovoltaic panel decreased with the rise of temperature. The short-circuit current, which increased slightly, was the exception. With the temperature increase, the efficiency of the tested panel decreased by approximately 0.5% per Kelvin.
In this paper the off-grid photovoltaic system consisting of a PV panel, MMPT charge controller and battery is described. The realization of a laboratory stand for charging or discharging batteries is presented. Original monitoring and control system, which is based on LabVIEW software and LabJack DAQ device, has been built. Data acquisition part, arithmetic part and front panel of program created in LabVIEW are described. Some problems with implementation of this system, providing the monitoring of electrical parameters, are mentioned.
The article presents the implementation of the estimation algorithms of orientation in 3D space and the displacement of an object in a 2D space. Moreover, a general orientation storage methods using Euler angles, quaternion and rotation matrix are presented. The experimental part presents the results of the complementary filter implementation. In the study experimental microprocessor module based on STM32f4 Discovery system and myRIO hardware platform equipped with FPGA were used. The attempt to track an object in two-dimensional space, which are showed in the final part of this article, were made with the use of the equipment mentioned above.
The realization of a laboratory stand for testing photovoltaic panels is presented here. The project of the laboratory stand was designed in SolidWorks software. The aim of the project was to control the electrical parameters of a PV panel. For this purpose a meter that measures electrical parameters i.e. voltage, current and power, was realized. The meter was created with the use of LabJack DAQ device and LabVIEW software. The presented results of measurements were obtained in different conditions (variable distance from the source of light, variable tilt angle of the panel). Current voltage characteristics of photovoltaic panel were created and all parameters could be detected in different conditions. The standard uncertainties of sample voltage, current, power measurements were calculated. The paper also gives basic information about power characteristics and efficiency of a solar cell.
A four-terminal (4T) bridge-circuit unconventionally supplied by two current sources connected in parallel to opposite
arms, named double current bridge (2J) has been presented. This circuit has been applied for experimental stress
analysis and worked with constantan foil strain gauges placed upon a beam. Some results of the measurements done
with two-active-gauge bridge and four-active-gauge bridge have been described. Some advantages of these bridge-circuit,
which could be used to the data acquisition during experimental measurements of a stress in a cantilever beam
and a simply supported beam have been mentioned.
In this paper the structure of a three-tiered distributed system for collecting and analysing medical examination data is presented. The idea of this work is to make an assistant tool for urologists to diagnose the lower urinary track diseases and their symptoms easier. The data (which are processed from the files made in the uroflowmeters - devices for measuring urine flow rate) are presented in web browser. It has been done with the use of PHP scripts which are accessed through Apache web server.
In this paper an original uroflowmeter (called Adalbertus) has been presented. The device draws the flow chart and measures the parameters of urine flow. It is used in urological surgeries as an assistance in diagnosis of lower urinary track diseases like Benign Prostatic Hyperplasia (BPH). The measuring track and its main part - weight sensor have been described. Also the way of uncertainty calculation is mentioned. An example flow chart has been shown and the achieved results have been compared with a commercial product.
On the basis of the previous investigations the new construction of measurement system with strain gage transducer
based on double current bridge is presented. The idea of measuring two different parameters at the same time in one
circuit-bridge is described. The system allows for measurement of axial and bending forces acting upon the beam.
A new type of circuit-bridge supplied unconventionally by two current sources will be discussed. An idea of this circuit has been suggested in some publications by Zygmunt Warsza under a name: double current bridge. The bridge conditioner makes possible to operate with the resistive sensors and to measure one, two or four parameters at one time. In this paper the relations between the arm currents and voltages of DC current supply bridges will be simulated. Also a sensitivity and a nonlinearity of these circuits will be discussed.