H-TGAPlot

GUI tool for Thermogravimetric Analysis (TGA / DrTGA) Visualization

Note: The software interface and menus are currently available only in Portuguese (Brazilian Portuguese).

H-TGAPlot is a Python desktop application for visualizing and quantitatively analyzing Thermogravimetric Analysis (TGA) and Derivative TGA (DrTGA / DTG) curves. It is part of the H-SciTools scientific software suite, developed to support materials engineering research.

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Features

Data loading

• Import .txt files exported by TGA instruments (Time Temp TGA DrTGA whitespace-delimited format)
• Automatic encoding detection (UTF-16, UTF-16-LE, UTF-8, Latin-1)
• Automatic extraction of the heating rate (°C/min) from the file header
• Multiple samples loaded simultaneously, managed from a sample list

Data processing

• TGA Y-axis as residual mass (%) or mass (mg); X-axis as temperature (°C) or time (s)
• DrTGA computed via Gaussian-filtered numerical derivative, selectable in mg/min, mg/s, mg/°C, %/min, %/s, or %/°C
• Optional Savitzky–Golay smoothing on the TGA curve (adjustable window size)
• Automatic onset/endset/mass-loss detection for up to N decomposition events, with automatic merging of overlapping events
• Manual interval analysis: define custom [T_start, T_end] ranges to compute onset, endset, midpoint, peak temperature, and both monotonic and raw mass loss

Style and appearance

• Color, line width, and line style configurable per sample (TGA and DrTGA curves colored independently)
• Sequential automatic color assignment (matplotlib tab10 palette)
• Independent X/Y grid toggle with automatic or fixed tick interval
• Adjustable font sizes for title, axis labels, ticks, legend, and event annotations
• 10 legend position presets (or automatic placement)

Graph interactivity

• Embedded matplotlib canvas directly in the main window, with the native navigation toolbar (zoom, pan, save)
• Draggable onset/endset/mass-loss annotation boxes
• Editable plot title, axis labels, and sample names from the side panel

Export

• PNG (300 DPI, white background, publication-ready)
• Event/interval results tables with one-click copy-to-clipboard (TSV) for pasting directly into Excel

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Interface

The layout is split into a scrollable control panel (left) and the plot area (right):

┌────────────────────┬──────────────────────────────────────────┐
│  H-TGAPlot          │                                          │
│  ─────────────      │                                          │
│  Files               │           Plot area                      │
│  Plot TGA/DrTGA      │       (interactive matplotlib)           │
│  Smoothing           │                                          │
│  Manual interval     │                                          │
│  Onset/Endset auto   │                                          │
│  ─────────────      │                                          │
│  Axes / Grid          │                                          │
│  Fonts / Legend       │                                          │
│  Style controls      │                                          │
│  Export              │                                          │
└────────────────────┴──────────────────────────────────────────┘

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Requirements

Python 3.9 or higher.

numpy
matplotlib
scipy

Install dependencies:

pip install numpy matplotlib scipy

tkinter is included in standard Python distributions. If missing on Linux, install via sudo apt install python3-tk. scipy is optional but strongly recommended — without it, smoothing and automatic onset/endset detection are disabled (the app still runs, with an on-screen warning).

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Usage

Running directly

python H-TGAPlot_v2_95.py

Packaging with PyInstaller

pyinstaller --onefile --windowed --icon=TGAPlot.ico H-TGAPlot_v2_95.py

The resulting executable in dist/ can be distributed without a Python installation.

The TGAPlot.ico icon file is optional. If not found, the application starts normally without an icon.

Workflow

1. Load files — choose one or more .txt TGA export files
2. Plot — render TGA, DrTGA, or both curves (dual Y-axis) for all loaded samples
3. Adjust signal processing — enable/tune TGA smoothing and DrTGA derivative smoothing as needed
4. Analyze — either enable automatic onset/endset detection or define manual temperature intervals for onset, endset, midpoint, and mass-loss calculations
5. Customize — adjust per-sample styles, axes, grid, fonts, and legend position
6. Export — save the figure as PNG, or copy event/interval result tables as TSV for Excel

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Supported file format

H-TGAPlot reads plain-text instrument export files (.txt, also tolerant of .dat / .tad extensions) containing a header line followed by four whitespace-separated numeric columns:

Time   Temp   TGA   DrTGA
<one blank/units line>
0.00   25.00   10.000   0.0000
0.50   25.30    9.998  -0.0012
...

Column	Physical quantity
Time	seconds
Temp	°C
TGA	mass (mg)
DrTGA	mass loss rate (mg/s)

If a line above the header contains two numbers in the pattern <heating rate °C/min> <hold temperature °C> (e.g. 20.00 1000.0), the heating rate is parsed automatically and used by the onset/endset algorithms.

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Code structure

H-TGAPlot_v2_95.py
│
├── resource_path()                   # PyInstaller-compatible asset resolver
├── analisar_intervalo_manual()       # Manual interval onset/endset/midpoint/mass-loss analysis
├── detectar_eventos_tga()            # Automatic multi-event onset/endset detection
├── _mesclar_eventos_sobrepostos()    # Merges overlapping detected events
├── _perda_monotonica()               # Monotonic accumulated mass-loss helper
├── Dataset                           # Per-sample data model (time, temp, TGA, DrTGA, style)
├── TGAModel                          # Core model: datasets, plot settings, intervals, events
├── GraficoEmbutido                   # Embedded matplotlib canvas with draggable annotations
│   ├── plotar_tga() / plotar_dtga() / plotar_ambos()
│   ├── redesenhar()
│   └── exportar_png()
└── App                                # Main tkinter window and side-panel UI

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Part of the H-SciTools suite

Tool	Purpose
H-AnodPlot	Electrochemical anodization curves
H-TGAPlot	Thermogravimetric Analysis (TGA)
H-DMAPlot	Dynamic Mechanical Analysis (DMA)
H-DRXPlot	X-Ray Diffraction (XRD)

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Author

Carlos Henrique Amaro da Silva

M.Sc. in Materials Technology and Industrial Processes — Universidade Feevale (2025)

B.Sc. in Chemical Engineering (2023)

Research focus: surface treatments, anodization, and electrodeposition with biomedical applications.

GitHub: https://github.com/Leindsher

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License

This project is licensed under the MIT License.