1 / 1

Low Temperature Heat Pulse Thermal Relaxation Calorimeter

Low Temperature Heat Pulse Thermal Relaxation Calorimeter. ●Principle The specific heat of a substance is defined as the quantity of heat required to raise the temperature of a unit mass of the substance by a unit degree of temperature. The heat capacity is then obtained as. ●Technique

ahanu
Download Presentation

Low Temperature Heat Pulse Thermal Relaxation Calorimeter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Low Temperature Heat PulseThermal Relaxation Calorimeter ●Principle The specific heat of a substance is defined as the quantity of heat required to raise the temperature of a unit mass of the substance by a unit degree of temperature. The heat capacity is then obtained as ●Technique The calorimetry technique used here is known as the time constant or relaxation method. It consists of changing step-wise the power supplied to the sample. The variations of heater power and chip temperature are sketched below. Power and temperature during a transient Sample mounting schematic chip The heat capacity is calculated by C= ד(1/RTH) =ד (∆P/∆T0),where RTH=∆T0/∆P is the effective thermal resistance involving sample, chip and wire. ד=time constant which can be obtained from the result of thermal transient. ●Experimental chart Transfer liquid helium into Dewar Check the needle valves in 1 K pot and sorb Put the probe into Dewar Vacuum the OVC of Dewar Cooling the He3 pot down to 0.5 K Cut the specimen into propersize (2 mg) Start the measurement Mount sample Put in the active carbon and connect T-cell with probe Put in the exchange gas into IVC (helium gas ) Vacuum the IVC of probe Put the probe into tank Bake active carbon ●Result Field dependence of C/T vs T2 Calibration of copper with various magnetic fields Schematic diagram of the insert of the calorimeter

More Related