MolDraw › Chemistry tools › TGA DSC Viewer
Free TGA and DSC Viewer
Open thermogravimetric (TGA) and differential scanning calorimetry (DSC) data. Find TGA steps with onset, DTG peak and mass loss, and read Tg, melting and crystallisation with ΔH and % crystallinity. Your files stay on your device.
or drop them here. CSV/TXT, TA Instruments, NETZSCH or METTLER text exports.
· Examples are simulated and free to reuse. Download the sample TA text file.
Settings
DSC crystallinity
Presets are typical literature values for ΔH100%. Published numbers spread, so check the one your field uses.
How to use the TGA and DSC viewer
- Open one or more files, or press an example button.
- Pick TGA, DSC or TGA + DSC, and the heating or cooling segment.
- Check the heating rate, the sample mass and which way endothermic is in your file.
- Read the TGA steps: onset, midpoint, DTG peak, mass loss and residue.
- Read the DSC events: Tg, melting and crystallisation with onset, peak and ΔH. Zoom to a peak and press Integrate current view to add one by hand.
- For crystallinity, pick a polymer or type ΔH100%, and set the polymer fraction for filled samples.
- Tick Add to compare to overlay more runs, then export a PNG or CSV.
Reading TGA and DSC curves
TGA (thermogravimetric analysis) weighs a sample while it heats. Each drop is a mass-loss step, such as water, solvent or decomposition. The DTG curve, the derivative of mass with temperature, turns each step into a peak, which makes overlapping steps easy to see. The mass left at the end is the residue, for example ash, filler or an oxide.
DSC (differential scanning calorimetry) measures the heat flow into a sample. The glass transition (Tg) is a step in the curve. Melting is an endothermic peak and crystallisation an exothermic one. The peak area gives the enthalpy ΔH in J/g, and comparing it with ΔH100% gives the crystallinity of a polymer. A pure metal such as indium checks the temperature and enthalpy calibration.
Frequently asked questions
Is my data uploaded?
No. Files are read and analysed in your browser only.
Which files can I open?
CSV or TXT with temperature (or time), mass or mass % and heat flow columns, TA Instruments Universal Analysis or TRIOS text exports (Sig lines and StartOfData), NETZSCH Proteus ASCII exports (## header line) and METTLER STARe table exports (Index, t, Ts, Value). Mass in mg is turned into % of the starting mass.
How is the TGA onset found?
With the tangent method. The tool draws the tangent at the steepest point of the step (the DTG peak) and finds where it meets the flat plateau before the step. The endset uses the plateau after the step. The midpoint is where half of the step's mass has gone.
Which way is endothermic?
Files differ. TA Instruments usually stores endotherms as negative (exo up). NETZSCH and METTLER usually store them as positive. The tool guesses from the file type and from the biggest peak. You can change "In the file, endothermic is" and pick endo up or exo up for the plot.
How is ΔH calculated?
The peak area above the baseline, divided by the heating rate. With heat flow in W/g and the rate in K/min, ΔH (J/g) = area (W·°C/g) × 60 / rate. Choose a straight (linear) baseline, or a sigmoid baseline for peaks where the baseline level changes across the peak.
How is % crystallinity calculated?
Xc = (ΔHm − |ΔHcc|) / (ΔH100% × w) × 100. ΔHm is the melting enthalpy, ΔHcc the cold crystallisation enthalpy, ΔH100% the enthalpy of a fully crystalline polymer and w the polymer weight fraction (100% if unfilled). The ΔH100% presets are typical literature values. Published values differ, so state the one you used.
Can I compare runs or show TGA and DSC together?
Yes. Tick Add to compare and open more files to overlay several runs. The TGA + DSC view puts mass on the left axis and heat flow on the right axis, for simultaneous (SDT/STA) data or two separate runs.