Local engineering calculation · research preview

Indicator Diagram Analyzer

Calculate pressure, work, load balance, compression behavior and combustion-timing indicators directly in your browser. Your CSV remains on your device.

Research use: Results depend on pressure referencing, TDC alignment, geometry, sampling resolution and calibration. They support engineering review and do not replace maker limits or a qualified diagnosis.

01 / INPUT

Load the pressure curve

Choose a CSV fileWide format: angle + one column per cylinder/cycle. Long format: angle, pressure, cylinder and cycle.

No local file selected

Data set representsEngine cyclePressure unitPressure basisBore (mm)Stroke (mm)Connecting rod (mm)Compression ratioEngine speed (rpm)Firing TDC in file (deg)Specific heat ratio γSelected angles (deg)

Advanced fitting windows

Compressionto

Expansionto

Combustionto

CSV QUICK GUIDE

Minimum data

angle_deg,cylinder_1,cylinder_2
-180,1.02,1.01
-179,1.03,1.02
..., ... , ...

One complete 360° cycle for a two-stroke engine.
One complete 720° cycle for a four-stroke engine.
Absolute pressure is preferred.
Use at least 1° resolution; 0.1–0.5° is better for dp/dθ.
Enter the firing TDC angle exactly as represented in the file.

The program applies light Savitzky–Golay smoothing before peak and derivative calculations. Raw values remain local and unchanged.