Simultaneous TGA-DSC Analyzer

What is the Simultaneous TGA-DSC Analyzer?

A simultaneous TGA-DSC analyzer couples a thermobalance with a calibrated heat-flow sensor, giving quantitative enthalpy and heat capacity together with mass loss from one sample. It is used for polymers, pharmaceuticals and organic materials.

Overview

The sample sits in a crucible on a heat-flow sensor plate carried by the thermobalance, with an empty reference crucible at the symmetric position. Indium calibration gives enthalpy values within about 2 percent, and specific heat can be obtained with a sapphire standard, so the instrument reports mass loss, derivative mass loss, heat flow and specific heat from a single run. Typical specifications are a temperature range from minus 150 to 700 degrees Celsius with cooling, balance resolution of 0.1 microgram, heat flow resolution of a few microwatts and heating rates from 0.1 to 50 degrees Celsius per minute. Applications include moisture and volatile content with melting behaviour, oxidative stability with associated exotherms, polymer composition where filler and additive steps must be matched to heat effects, and pharmaceutical hydrate and polymorph studies where dehydration and melting overlap.

How does it work?

The instrument combines a thermobalance with a heat-flow or differential thermal sensor on a single sample holder inside one furnace, so mass and thermal signals share exactly the same temperature, heating rate and atmosphere. Because there is no second sample, results cannot be offset by sample-to-sample variation in mass, particle size or packing, which is the main advantage over running a TGA and a DSC separately. The heat-flow signal can be calibrated with indium to give melting enthalpies and heat capacity, while the balance gives mass loss steps, derivative peaks and residue. Typical temperature ranges extend from ambient to 1500 or 1600 degrees Celsius, with balance resolution of 0.1 microgram and heating rates of 0.1 to 50 degrees Celsius per minute. Purge gas is switched between inert and oxidising conditions, and a reference crucible is placed on the sensor alongside the sample crucible.

What are the key features?

• Heat-flow sensor calibrated with indium for quantitative enthalpy
• Mass, derivative mass, heat flow and specific heat in one run
• Temperature range from −150 to 700 °C with cooling accessory
• Balance resolution of 0.1 µg with symmetric reference crucible
• Gas switching between inert and oxidising atmospheres during a run
• Software with combined mass and heat flow evaluation

What are the technical specifications?

A typical simultaneous tga-dsc analyzer configuration offers temperature range of −150–700 °C, balance resolution of 0.1 µg, heat flow resolution of 1–5 µW, calorimetric accuracy of ±2% with indium, heating rate of 0.1–50 °C/min and sample mass of 5–30 mg typical. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Simultaneous TGA-DSC Analyzer is used in polymer moisture, filler and additive analysis, pharmaceutical hydrate and polymorph studies, oxidative stability with exotherm detection, food composition and thermal behaviour and adhesive and coating formulation. Across the wider Simultaneous Thermal Analyzers class, laboratories also deploy it for polymer composition and additive analysis, pharmaceutical hydrate and polymorph studies and ceramic and mineral reaction analysis.

Which standards and certifications apply?

Relevant standards and methods include ASTM E1131, ASTM E967, ASTM E794, ISO 11358-1, ISO 11357-1 and USP <891>. Certification candidates for this model are CE, IEC 61010-1 safety and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Prepare sample and reference crucibles in the same way, with similar mass and packing, because the heat-flow signal depends on the symmetry of the two positions. Keep the balance purge flow stable and high enough to protect the weighing mechanism from condensable products, and verify with a blank run whenever the gas or flow changes. Calibrate temperature with Curie-point or melting-point standards and heat flow with indium before a critical campaign, and record crucible type, gas, flow, heating rate and sample mass with each curve. Simultaneous instruments show artefacts when the two crucibles differ: a sloping or drifting heat-flow baseline usually means asymmetry, damaged crucibles or contaminated sensors. Coupled techniques add transfer line maintenance, and the interface temperature must always be above the dew point of the evolved gases.

How do I select the right Simultaneous TGA-DSC Analyzer?

Choose the TGA-DSC configuration when quantitative heat effects must accompany mass loss, as in pharmaceutical or polymer studies. If peak temperatures alone are needed at higher temperatures, a TGA-DTA sensor performs better. In an RFQ, specify temperature range, crucible types, gas control, autosampler and calibration standards.

How does it compare with other Simultaneous Thermal Analyzers variants?

Choose between the TGA-DSC and TGA-DTA sensor types first. A heat-flow sensor calibrated with indium gives quantitative enthalpies and heat capacity and suits polymers, pharmaceuticals and organics; a DTA sensor is more robust at high temperature and suits ceramics, minerals and metals where peak temperatures are enough. Then set the temperature range, since inorganic materials may need 1500 or 1600 degrees Celsius while organics require sub-ambient cooling. Decide whether evolved gases must be identified, which determines whether an FTIR or mass spectrometer coupling is needed. Check balance resolution, whether the crucible arrangement allows gas to flow over the sample, the gas switching capability, the software for combined signal evaluation and the calibration standards provided. For quality control, an autosampler converts the instrument into an unattended routine analyzer.