New Thermo-Optical Plants for Laboratory Experiments

The resonant-mirror technique makes it possible to measure very small chemically induced changes in the refractive index of a surface layer. These small changes in refractive index can be masked by small changes in the temperature of the surface. By measuring the temperature close to the surface with a stable thermistor and digitizing the thermistor output to 20 bits it proved possible to use a microcontroller to drive a Peltier junction via a switching amplifier to stabilize this temperature to within ±1 mK within the range 4–38 • C.

1994

The effort is divided into specific topics applicable to data processing. Those topics include the Dember effect, alignment of a ring laser gyro, measurement of the Fresnel drag coefficient, integrated optical switches, aluminum gallium arsenide waveguides, Fredkin gates, optically reconfigurable superconductive circuits, and an initial investigation into the application of an acoustooptical tunable filter to the interrogation of fiber optic Bragg sensors.

2008 IEEE Instrumentation and Measurement Technology Conference, 2008

The paper presents the first step to the building of a distant experiment, in the framework of remove physical laboratory directed via internet. It deals with the measurements of the basic characteristics of electrical voltage source. The individual parts of arrangement were realized by the ISES kit, that is able to command the measuring procedures and to transform the corresponding values via computer.

Archives of Control Sciences, 2014

This paper presents a gain scheduled controller design for MIMO and SISO systems in the frequency domain using the genetic algorithms approach. The proposed method is derived from the M-delta structure of closed loop MIMO (SISO) systems and the small gain theory is exploited to obtain the stability condition. An example of real system illustrates the effectiveness of the proposed output feedback gain scheduled controller design method and also the possibility to improve its performance using the genetic algorithm

Data in Brief, 2020

The operation of an associated low-cost thermoluminescence (TL) system [1] necessitated the design and construction of a precision temperature controller. The temperature controller is presented separately since it is a crucial aspect of the TL system. The overarching design condition was a tightly controllable temperature regime with a resolution of about ±0.5 • C. The system was designed in such a way that an embedded controller formed around the PIC18f2520 heats up a sample holder to a specified temperature in optimal time while monitoring the temperature. The control algorithm was then written to ramp the temperature through the desired range of temperature between 25 and 700 • C. The output of the PID controller was made to drive a resistive heater element or plant, modelled as a low-delay component owing to the small size of the sample holder. A mathematical model of the plant was obtained, simulated within MATLAB and the optimal controller found. The results of the simulation...

To learn and manipulate the wave nature of light, for purpose of teaching, we designed and set up an optical communication system using low cost laser diodes and multiplexing holograms. Making use of the wave nature of light, different kind of information could be send using different wavelengths appropriated to perform a multiplexing effect. By making several beams of light, each modulated in amplitude by dissimilar analogical or digital signals, to impinge simultaneously on a holographic grid, which send the beams thorough some kind of waveguide that can be an optical fiber. At the output where information was received, a similar grid was used to separate the different information carriers, each being addressed towards different corresponding photo detectors for demodulating the desired information. Modulation of laser light was realized by standard simple electrical circuits, which bring out different kind of information. For example, audio signals, radio transmitters, cell phones, portative sound reproducers. In addition, by simple standard circuits for the photo detectors we could convert intensity light variations into electrical signal differences, for each wavelength, which lead to the final information retrieval using corresponding transducers, as loudspeakers, which is the final stage for the information originally sent throughout optical signal variations. The proposed method was tested with a 17 students with favorable results, encouraging the authors for designing new experiments with the same idea of making a more dynamical active learning to help the students to develop new skills and more effective training in optical engineering and applications. Abstract Con propósito de enseñanza, hemos diseñado y creado un sistema de comunicación óptica, utilizando diodos láser de bajo coste y hologramas de multiplexación, para aprender y manipular la naturaleza ondulatoria de la luz. Haciendo uso de la naturaleza ondulatoria de la luz, diferentes tipos de información se podrían enviar usando diferentes longitudes de onda apropiada para realizar un efecto de multiplexación. Al hacer varios haces de luz, cada uno modulado en amplitud por señales analógicas o digitales diferentes, que inciden simultáneamente sobre una rejilla holográfica, que envían las haces mediante algún tipo de guía de ondas que puede ser una fibra óptica. En la salida donde se recibió información, una rejilla similar se utilizó para separar los diferentes soportes de información, cada uno dirigido hacia diferentes fotodetectores correspondientes a la demodulación de la información deseada. La modulación de la luz láser se realizó por medio de circuitos eléctricos simples estándar que llevan a cabo diferentes tipos de información; por ejemplo: señales de audio, transmisores de radio, teléfonos celulares, reproductores portátiles de sonido. Además, con circuitos estándar simples para los fotodetectores, podríamos convertir las variaciones de intensidad de luz en diferencias de señal eléctrica, para cada longitud de onda, que conduzcan a la recuperación de la información final, utilizando los transductores correspondientes, como altavoces. Esa es la etapa final de la información enviada originalmente, a través de variaciones de la señal óptica. El método propuesto se probó con unos diecisiete estudiantes, con resultados favorables. Esto animó a los autores al diseño de nuevos experimentos, con la misma idea de hacer un aprendizaje activo más dinámico, para ayudar a los estudiantes a desarrollar nuevas habilidades y una formación más eficaz en la ingeniería óptica y aplicaciones.

2012

This paper describes the experiences using remote laboratories for thorough analysis of a thermal system, including disturbances. Remote laboratories for education in subjects of control, is a common resorted method, used by universities. This method is applied to offer a flexible service in schedules so as to obtain greater and better results of available resources. Remote laboratories have been used for controlling physical devices remotely. Furthermore, remote labs have been used for transfer function identification of real equipment. Nevertheless, remote analyses of disturbances have not been done. The aim of this contribution is thereby to apply the experience of remote laboratories in the study of disturbances. Some experiments are carried out to demonstrate the effectiveness in using remote laboratories for complete analysis of a thermal system. Considering the remote access to thermal system, “Sistema de Laboratorios a Distancia” (SLD) was used.

Journal of Analytical Chromatography and Spectroscopy, 2018

The complex of investigations of optical characteristics of controlled objects and spectral symmetric-wave and two-colour compensating thermometry (SWT and TCCT) influence on their errors of method and instrumental errors is performed. Advantages of these new methods in the field of errors of method, in comparison with known spectral and also classical energy and spectral ratio thermometry are proved. It is established that right use of the SWT and the TCCT, which takes into account thermometrical conditions, allows to completely exclude methodical and instrumental components from the errors of optical temperature measurements. Spectral thermometry is based on remote quantitative determination of the spectral emissivity distributions of controlled objects. Using these distributions and well-known relationships between the spectral coefficients of emission, absorption, reflection and transmission we can determine macro-optical characteristics of these objects and remotely investigate...