Simple structure, stable and reliable
The heat required for a substance of unit mass to rise temperature 1 K (1 °C) is called the specific heat capacity of the substance, and its value varies with temperature. According to Newton's cooling law, cooling method is one of the common methods for measuring the specific heat capacity of metals. If the specific heat capacity at different temperatures of a standard sample is known, the specific heat capacity at different temperatures of various metals can be measured by using the cooling curve.
The LETI-12, Apparatus of Measuring Specific Heat Capacity, is designed with a few innovations compared with the traditional experimental methods and experimental instruments. In the aspect of experimental method, the cooling conditions of the sample are no longer only natural cooling in room temperature environment, but also use a fan to create forced convection for cooling environment. The advantages and disadvantages of the two cooling conditions can be compared and analyzed. In the aspect of experimental device, the heating device is a PTC heating plate working at a safe voltage with temperature limiting. A temperature sensor of PT100 resistance is used to replace the traditional Copper-constantan thermocouple that needs an icy reference end to work. The sample chamber is changed from the traditional up and down vertical structure to the left and right horizontal structure. The heater movement in the sample chamber is also changed from up and down to left and right, making the experimental operation more convenient.
This apparatus takes copper as the standard sample and measures the specific heat capacity of iron and aluminum samples at 100 °C under two different cooling environments, i.e. forced convective cooling and natural cooling, enables students to understand the relationship between the cooling rate of metal and the cooling environment, and master the experimental method of measuring specific heat capacity of metal by cooling.
This experimental apparatus mainly consists of a main electric unit, a heater, a sample chamber, a cooling fan, a PT100 platinum resistance, and so on. Using this apparatus, the following experiments can be performed:
1. Learn to measure temperature using PT100 platinum resistance;
2. Under forced convective cooling, measure specific heat capacity of iron and aluminum samples at 100 °C;
3. Under natural cooling, measure specific heat capacity of iron and aluminum samples at 100 °C.
The instruction manual contains experimental configurations, principles, step-by-step instructions, and examples of experiment results. Please click Experiment Theory and Contents to find more information about this apparatus.
working voltage 30 VAC
stable temperature > 200 °C
temperature limiting 260 °C
|Digital Ohm meter||0 ~ 199.99 Ω, resolution 0.01 Ω|
|Metal sample||copper, iron and aluminum, each one, length 65 mm, diameter 8 mm|
|Sample chamber||1 (including heater, fan, PT100)|
|Sample||3 (copper, iron, aluminum)|