Stanowisko dydaktyczne do pomiaru temperatury wybranymi metodami

W pracy przedstawiono stanowisko dydaktyczne służące do pomiaru temperatury z zastosowaniem metod zarówno stykowych jak i bezkontaktowych. Zakres metod stykowych obejmuje pomiary termoelementem, termistorem ale również z zastosowaniem ogniwa Peltiera. Metodą bezstykową jest pomiar termograficzny z zastosowaniem kamery termowizyjnej. Zwiększenie temperatury powyżej temperatury otoczenia zrealizowane zostało przy pomocy ogniwa Peltiera. Przedstawiono przykładowe wyniki pomiarów w postaci charakterystyk temperaturowych oraz ich analizę. Najciekawszym zagadnieniem w pracy jest zastosowanie ogniwa Peltiera do pomiaru temperatury. Jest to zagadnienie praktycznie nie znane studentom.

Temperature is the most often measured physical quantity as in normal life as in industry. So, it is very important to teach students about methods and sensors for temperature measuring. The main goal of this paper is presenting didactic stand for temperature measurement. It enables to measure temperature with contact and contactless methods. General description of measurement is presented as well as example measurement results with discussion. The element which changes temperature is Peltier’s Cell which is supplied by Power Supply. The simple circuit is presented in fig. 2. The Peltier’s Cell is switched between Peltier’s effect and Seebec’s effect using 1-2 switch (see fig. 2). There are two thermocouple sensors: one on the hot size, second on cold one and thermistor on the hot size. The exact installation of the sensors is presented in fig. 1. The IR camera Flir A325 is applied as well for sensorless measurement, the example of thermogram is presented in fig. 5. Figures 4, 6, 7, 8 and 9 present exemplary results for measurements. Fig. 4 presents temperature measurement for hot and cold size using thermocouples and IR camera. Fig. 6 presents thermocouple Seebeck’s voltage vs. temperature. Figs. 7 and 8 presents Peltier’s Cell Seebeck’s voltage and power vs. hot/cold difference of temperatures. Fig 9 presents thermistor resistance vs. temperature. The two electric circuits are presented in Fig. 3 for resistance-voltage conversion, the results for conversion are presented in fig. 10, there are used voltage divider and current mirror. The measurement stand enables to teach students variety methods of temperature measurement classical contact methods using thermocouples and thermistors, contactless method using IR camera and non popular method using Peltier’s Cell. The last possibility is surprising for students. It is used as example of “energy havesting” solution.