Calorimetry is a technique that measures the heat involved in a chemical reaction or phase change. The best way to understand the difference between differential scanning calorimetry (DSC) and differential thermal analysis (DTA) is to look at their processes. Although they both record temperature changes yet they have different objectives.
DSC vs DTA
The main difference between DSC and DTA is that DSC is a thermogravimetric analysis that looks at the change in temperature of a substance over time due to heat changes. DTA, on the other hand, is a thermoanalytical technique that measures temperature change to uncover the thermal properties of a sample.
Differential scanning calorimetry (DSC) is a type of thermal analysis that provides information about a substance’s thermal behaviour. It is used to examine phase changes, such as melting and freezing, as well as other physical and chemical processes. It is a common technique used in polymer science and engineering, pharmaceuticals, and many other fields.
Differential thermal analysis is a method of testing that allows you to compare the thermal conductivity of two materials at different temperatures. This is done by heating one sample while the other is kept at a cooler temperature, called the reference temperature. The results from this test are usually used to compare the thermal conductivity of the materials being tested or to see if the material being tested is an insulator or a conductor.
Comparison Table Between DSC and DTA
Parameters of Comparison | DSC | DTA |
Full-Form | DSC is the abbreviation of Differential Scanning Calorimetry. | DTA is the abbreviation of Differential Thermal Analysis. |
Introduced By | It was introduced by Watson and Neil. | It was introduced by Le- Chateliar. |
Basis | DSC measured heat flow in a substance. | DTA measures temperature changes. |
Use | It is best suited to find characteristic temperatures of different substances. | It is best suited to find certain values like temperature of fusion or other caloric values. |
Accuracy | It is very precise as temperature changes are recorded along with the concept of heat flow. | It’s is less accurate than DSC. |
What is DSC?
Differential scanning calorimetry is a technique used by scientists to find out the melting point of a substance. By placing a substance in a closed container, putting it under high pressure and monitoring the temperature changes, a graph can be made which shows the melting point. A differential scanning calorimeter is used to determine the heat changes over time.
Using a known calibration curve, the melting point can be determined. The equation is Q=mcΔT. This technique is important in pharmaceutical research because it can help determine whether different dosage forms of the same drug have the same amount of active ingredients. It can also be used to determine the degradation temperature of polymers like polyethene terephthalate.
Differential Scanning Calorimetry or DSC is an analytical technique that is used to examine the thermal properties of a substance. To do this, the substance under analysis is placed inside a sealed chamber that is heated. The instruments used to carry out DSC usually vary in size and complexity, with the simpler models doing only temperature measurements of the sample, while the more complex versions are capable of measuring the kinetic energy of phase changes as well.
This not only a graphical representation is made on the temperature changes but also the heat flow is being considered.
What is DTA?
Differential thermal analysis is a technique that is used to determine the thermal properties of thermal conductivity and thermal expansion. This method of testing analyzes the thermal conductivity of metals, polymer, and ceramics. The thermal conductivity defines the rate of heat transfer of the material as it experiences a change in temperature, which is measured in W/m2•K.
The thermal expansion of the material describes the material’s tendency to expand when heated, which is measured in m/m•K. These are important measurements for material scientists and engineers. Since the development of differential thermal analysis (DTA), or thermogravimetry (TG)/DTG, has become a routine technique in characterizing materials of interest to scientists and engineers.
It is a thermal analysis technique that measures mass loss as a function of temperature. DTA/TG/DTG is commonly used to identify the endothermic and exothermic reaction of material, including the onset and completion of the reaction, and to measure the thermal stability of a material. The technique is also used to provide information on a material’s purity and the components present, i.e. the chemical composition.
Differential scanning calorimetry is a test designed to show the thermal properties of a material. This test is performed by determining how much energy is required to increase the temperature of a material under constant pressure. Differential thermal analysis is a similar test that measures how much energy is required to increase the temperature of a material under constant temperature.
Main Differences Between DSC and DTA
- An energy curve is created when using differential scanning calorimetry, whereas the difference between the peak point and the baseline depends on the thermal analysis.
- Compared to differential scanning calorimetry, DTA is a less precise method and is often used to detect the difference in the properties of a material.
- Differential scanning calorimetry (DSC) is a technique that measures the changes in heat flow going from one thermodynamic state to another. It can be used to determine the melting point of the substance from the heat given off by the transition from solid to liquid. In differential thermal analysis (DTA), the heat flow is measured as a temperature gradient (delta T) is applied to a sample. DTA can be used to determine the transition temperatures of a substance.
- One of the main differences between DSC and DTA is that DTA also measures the change in enthalpy while DSC does not.
- DSC is used to analyze biologically active elements like enzymes, minerals and so on, while DTA is used to analyze proteins and antibiotics and antibodies.
Conclusion
Theory and Practice of the DSC Differential Scanning Calorimetry (DSC) and Differential Thermal Analysis (DTA) are used for the determination of thermal properties of materials and the study of phase transformations that occur in the material in response to a temperature change.
Following the development of first-generation calorimeters, the understanding of the physical principles of calorimetry has advanced, including the expanded scope of the technique and the development of improved instrumentation and software. The evolution of theory and practice of differential calorimeter and differential thermal analyzer has led to the development of standards for terminology and procedures for calibration and measurement for both techniques.
References
- https://books.google.com/books?hl=en&lr=&id=tRt-Z5Duz7QC&oi=fnd&pg=PA1&dq=differential+scanning+calorimetry&ots=7F1UnOFcFU&sig=iufmQP_EI-XA-F9TRiKreCBAl1Y
- https://pubs.acs.org/doi/pdf/10.1021/ac60030a011