Mettler thermal analysis system

Differential scanning calorimetry is primarily used to determine changes in proteins as a function of temperature. The instrument used is a thermal analysis system, for example a Mettler DSC model 821e. The instrument coupled with a computer can quickly provide a thermal analysis of the protein solution and a control solution (no protein). The instrument contains two pans with separate heaters underneath each pan, one for the protein solution and one for the control solution that contains no protein. Each pan is heated at a predetermined equal rate. The pan with the protein will take more heat to keep the temperature of this pan increasing at the same rate of the control pan. The DSC instrument determines the amount of heat (energy) the sample pan heater has to put out to keep the rates equal. The computer graphs the temperature as a function of the difference in heat output from both pans. Through a series of equations, the heat capacity (Cp) can be determined (Freire 1995). 

Three to 4 mg of extracted biopolymers was encapsulated in aluminum pans for the measurements. Each sample was first annealed at 200°C for 3 min. The melting point was determined using a Mettler DSC 30 Thermal Analysis System. Dry nitrogen was used as the flow gas with a flow rate of 30 mL/min, calibrated with indium and mercury. 

We have used in this work, the Mettler TA2000B thermal analysis system and the supplied Kinetic and Applied Kinetic Programs. This instrument and associated software is capable of analyzing on-line the nth-order equation (1.1). 

Instrumental. The Mettler TA2000B thermal analysis system is equipped with an interface system, and Hewlett-Packard 9815 desk top calculator and 7225 plotter. Samples, weighing 5-10 mg, sealed in aluminum pans and under a nitrogen blanket, were heated in the calorimeter at a rate of 10 deg/min from -35 or 10 deg C to 180 deg C respectively, for specific heat and kinetic scans. Specific heat measurements were calibrated with alumina to an accuracy of 3%. Temperatures and enthalpies were calibrated with an Indium sample. The accuracies were .02 deg C and 2% (Indium 28.5 J/g), respectively. 

The Mettler TMA 40 thermomechanical analyzer is illustrated in Figure 11.3. A measuring sensor applies a user-definable force to the sample of -0.05-0.5 N. The position of the sensor is continuously monitored by a LVDT. TMA measurements can be made in the temperature range -100-1000 C. This module is part of the Mettler TA 3000 thermal analysis system. 

Thermal analysis is a technique for characterizing materials by measuring changes in physical or chemical properties resulting from controlled changes in temperature. Systems include DSC, TGA, DMA, TMA and DTA. Companies like Du Pont, Mettler and Perkin Elmer have developed systems, each of which can be used with its own modular control system switching to the thermal analysis system in use, but of course only the system selected can be controlled at any one time. 

The next diagram, on the left, displays a top view of the heat leak disk of the Mettler DSC 20 and 25 thermal analysis systems. The disk is made out of quartz with a vapor-deposited 10-junction thermopile. The reference and sample crucibles each sit on one of the two circularly arranged spots with five or more sensors. The two central terminals bring the temperature difference signal to the measuring module. Absolute temperature information and... 

ARC = Accelerating Rate Calorimeter (Columbia Scientific Instrument Corp.) DSC = Differential Scanning Calorimeter DTA = Differential Thermal Analysis RC1 = Reactor Calorimeter (Mettler-Toledo Inc.) RSST = Reactive System Screening Tool (Fauske and Associates) VSP = Vent Size Package (Fauske and Associates) ... 

The purpose of differential thermal systems is to record the difference in the enthalpy changes that occurs between the reference and the test sample when both are heated in an identical fashion. Several publications are available concerning the theoretical aspects and applications of various thermal analysis techniques, including the DSC [71-74]. Commercial instruments are available from a number of companies including Perkin-Elmer, TA Instruments, Toledo-Mettler, SET ARAM, Seiko, and Polymer Laboratories. 

The thermal stability of the complexes was determined by thermo gravimetric analysis (TGA) with a Mettler TA 3000 System at a scan rate of 10°C/min under nitrogen atmosphere. The complexes were found quite stable up to 430 °C. The maximum weight loss occurred at about 450 °C. 

Thermal analysis. A Mettler TA2000 system was used for TGA. The analyses, on supports and catalysts, were performed under CO2+ CH4 (1 1) at atmospheric pressure in isothermal conditions at 823, 873, 923 K with the H2 initial reduction and H2 final treatment (60 min He purge after each gas change). 

Two other important milestones in the development of the modern thermobalance occurred in 1958 and 1964. A multifunctional instrument, called the Derivatograph. was described by Paulik 35) et al. in 1958. The instrument could record not only the TG curve, but also its first derivative (DTG) and the differential thermal analysis jDTA) curve. In 1964. Weide-mann (3) described the Mettler system, which was perhaps the most sophisticated thermobalance ever commercially available. This system is described in detail by Wiedemann and Bayer (8). 

The thermal property of sisal fiber was studied at AMPRI Bhopal using the Mettler Toledo STAR System by thermo gravimetric curve and differential thermo gravimetric curve, as shown in Fig. 22.6a, b. The temperature range used for analysis was from 500°C to 800°C. Results revealed that in the temperature range of 50°C-200°C, dehydration as well as degradation of lignin occurred. But, at... 

Websites with thermal analysis instruments and apphcations include TA Instruments, www.tainstru-ments.com Mettler Toledo, wwwjnt.com PerkinElmer, www.peikinetmer.com NETZSCH Instruments, www.netzsch-thermal-analysis.com Setaram Instrumentation, www.setaram.com Expert System Solutions, www.expertsystemsolutions.com Shimadzu Scientific Instruments, www.ssi.shimadzu.com Hitachi High Tech Science Corporation, www.hitachi-hitec-science.com and GE Healthcare Life Sciences, www.gelifesciences.com. 

Because of the suspected decomposition of anhydrite, CaSO4, in lithium-based tetraborate flux systems at elevated temperatures, it was decided to study their behavior by means of thennal analysis (TGA, DTA). Thermal scans were performed on the Mettler TA-2 thermoanalyzer equipped with a DTA-20 macroholder. Platinum crucibles were filled with 200 mg of specimen flux mixtures and balanced by equal portions of alumina as the reference material. All specimens were heated at a rate of 10 C/min in an oxidation atmosphere (stream of air). 

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