Performance and calibration of the Flash DSC 1, a new, MEMS-based fast scanning calorimeter
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Performance and calibration of the Flash DSC 1, a new, MEMS-based fast scanning calorimeter Geert Vanden Poel • Daniel Istrate • Agnieszka Magon • Vincent Mathot
Received: 10 May 2012 / Accepted: 21 September 2012 / Published online: 17 October 2012 Akade´miai Kiado´, Budapest, Hungary 2012
Abstract For the new Flash DSC 1, the temperature windows-to-operate—the temperature ranges where the real, achieved scan rate is constant—have been determined for unloaded sensors under various conditions like purge gas and flow rate variations; cooling to -90 C and heating to 450 C; scan rates from 1 up to 20,000 C s-1 in heating and 15,000 C s-1 in cooling. Compared to nitrogen, helium purge gas offers better access to low-temperature transitions and enables faster cooling. Drawback is the decreased temperature window-to-operate in heating at the high-temperature side. The temperature calibration protocol according to the recent DIN SPEC 91127 for sample mass and scan rate was found to be useful. The correction factors are maximal -1.4 C as measured for 1 lg at 1,000 C s-1 heating. Using liquid crystalline substances it was proved that the Flash DSC 1 has symmetry, meaning that calibration data found in heating also can be applied in cooling. Keywords MEMS Chip sensor Temperature calibration Purge gas Purge gas flow rate Sample handling Symmetry
G. V. Poel (&) D. Istrate A. Magon DSM Resolve, Geleen, The Netherlands e-mail: [email protected] A. Magon Department of Chemistry, Rzeszo´w University of Technology, 35-959 Rzeszow, Poland V. Mathot SciTe, Geleen, The Netherlands
Introduction The endeavour to realize much faster temperature–time scan rates than has been possible hitherto, has led in recent years to crucial innovations in the field of thermal analysis and calorimetry [1–12] namely the development of various types of fast scanning calorimeters (FSC’s) capable to vary the scan rate several orders of magnitude. Parallel to this development various existing Standard DSC’s have been revisited to explore the boundaries of their capabilities in this respect to get the maximum benefit of the equipment. One of the reasons for this development is the awareness that many systems—polymers, pharmaceuticals, metals etc.—are not in thermodynamic equilibrium, denoted as being ‘metastable’, causing such systems to be vulnerable to temperature–time fluctuations and ramps, occurring spontaneous or imposed as during processing. The capability to realize the exact temperature–time treatment using FSC as applied in real industrial processes allows investigation of the resulting properties of the material. The thermal history is one of the main drivers which strongly influences these end properties; especially when—often (very) high—rates of cooling are involved along the processing. These high scan rates will definitely change the solidification behaviour of the material which is reflected by the change of the crystallization temperature distribution and characteristic temperatures like the peak maximum te
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