OCR-based pressure monitoring tool for Waters Alliance HPLC instruments.
This tool reads the pressure value displayed in the instrument software using OCR and calculates pressure deltas over 30 and 60 seconds (PSI) to help detect pressure instability during operation.
The program runs as a lightweight transparent overlay window that can be positioned over the instrument software interface.
🇧🇷 Portuguese version available in LEIAME.md
This software is a personal project created to meet specific needs in my workflow.
It is not an official product of Waters Corporation, and there is no sponsorship, partnership, or affiliation with the company.
Use of this software is at your own risk, and it does not replace or modify any official Empower 3 functionality.
This application captures only a small region of the screen in order to perform OCR on the pressure value displayed by the instrument software.
- No screenshots are stored
- No data is logged
- No information is transmitted externally
- The program operates entirely locally
- Real-time OCR pressure reading
- Pressure delta calculation over 30 seconds and 60 seconds
- Transparent overlay window
- Resettable runtime timer
- Lightweight GUI built with Tkinter
- Standalone Windows executable
- Runs entirely offline
In the Empower 3 software, open the Instrument Status panel.
In case it's not already visible, this window can usually be accessed through the following menu:
View → Toolbars → Flow/Pressure
Run:
AllianceDeltaMonitor.exe
A small transparent overlay window will appear.
Move the overlay window so that the capture area is positioned over the Pressure (psi) value displayed in the Instrument Status window.
Alignment guidelines:
- The monitored value is Pressure (psi).
- Align the capture area with the numeric pressure value.
- If necessary, prioritize capturing the numbers themselves, even if the text label "Pressure (psi)" is partially outside the capture area.
- Make sure the numbers are clearly visible and unobstructed.
Once aligned correctly, the software will automatically begin reading the pressure and calculating deltas.
The Reset button performs two actions:
- Resets the runtime timer
- Clears the pressure history used for delta calculations
After pressing Reset, the application begins a new monitoring cycle, recalculating the 30-second and 60-second pressure deltas from the new readings.
Example interface:
Install dependencies:
pip install -r requirements.txt
Run the program:
python delta_pressure.py
A compiled Windows executable is available in the Releases section.
Download:
AllianceDeltaMonitor.exe
No Python installation is required.
To build the executable manually using PyInstaller:
pyinstaller --noconfirm --windowed \
--name AllianceDeltaMonitor \
--icon=delta.ico \
--version-file build_tools/version.txt \
--add-data "tesseract;tesseract" \
--add-data "delta.ico;." \
delta_pressure.py
Try the following:
- Ensure the pressure numbers are clearly visible
- Avoid overlapping windows
- Align the capture area closer to the numeric value
- Ensure sufficient screen contrast
OCR accuracy depends on the visibility and clarity of the numbers on screen.
Lucas Albuquerque
This project is licensed under the MIT License.