Basic Information

Abstract Number: 680 - 3
Author Name: Robert Danley - TA Instruments
Session Title: The Twenty-Sixth James L Waters Symposium: Thermal Analysis Instrumentation
Event Type: Symposia
Event Title: From Thermometry to Differential Thermal Analysis to Differential Scanning Calorimetry, Key Developments in DSC

Presider Name:Annette S Wilson
Affiliation:University of Pittsburgh

Date: Monday, March 9, 2015
Start Time: 02:10 PM (Slot #3)
Location: 245

Abstract Content

The first thermal analysis measurements were made during the 19th century when cooling curves were used to investigate phase transitions. Roberts-Austen created the first differential thermal analysis instrument by adding a second thermocouple to measure the difference in temperature between the sample and an inert reference. This increased the sensitivity of the apparatus. The temperature difference measurement combined with a sample temperature measurement remains the basis for all modern differential thermal analysis and DSC. Vold applied a heat transfer analysis to her differential thermal analysis instrument to obtain sample heats of transformation, thus adding quantitative heat flow rate measurements, i.e. scanning calorimetry to differential thermal analysis. The lumped heat capacity formulation she employed continues to be the basis for obtaining heat flow information from DSC. Boersma described a differential thermal analysis instrument having high thermal conductivity sample and reference holders configured such that the differential temperature measurement was largely independent of the sample thermal conductivity, improving the reproducibility of the differential temperature measurement and hence increased precision of heats of transition. The early 1960s saw the introduction of the first commercial DSCs and the name differential scanning calorimeter was first used. Power compensation DSC was introduced along with heat flow DSC derived directly from differential thermal analysis. Temperature modulated DSC developed by Reading added periodic temperature oscillations to temperature scanning, allowing the resulting heat flow signal to be separated into a heat flow due to the sample heat capacity and a heat flow due to latent effects such as crystallization. Rapid heating and chip DSC have recently been developed that expand heating and cooling rates up to 105 K/min and beyond to facilitate analysis of metastable materials.