σT

σT is a precision tool for physics students and researchers who need to propagate measurement uncertainties through calculations. Enter your experimental data, and σT handles the error math automatically. **FIVE ERROR MODES** Configure uncertainties in your data to match your orignal measurement method: • Constant — for physical constants and exact values • Absolute — fixed ±error (ruler measurements, digital readouts) • Relative — percentage-based uncertainty • Combined — both absolute and relative components (many typical multimeters) • Per-Value — individual error for each measurement **AUTOMATIC PROPAGATION** Create derived values and watch uncertainties flow through the calculation chain. σT uses Gaussian error-propagation and pre-calculated derivative-based methods to compute propagated errors correctly when combining independently measured variables. Available operations: • Basic: add, subtract, multiply, divide, reciprocal • Functions: exp, ln, sin, cos, normalize • Statistical & Sample Statistics: mean with standard error, average step width • Advanced: weighted sums, weighted products, polynomials • Physics: Lorentz factor (relativistic gamma), Logit sigmoid (Fermi-Dirac statistics) **INTERACTIVE CHARTS** Visualize your data with proper error bars. Pinch to zoom, drag to pan, double-tap to auto-fit. Add mathematical function overlays to compare your measurements against theoretical predictions, identify eligible parameter ranges matching your measurements. **EXPORT YOUR WORK** • CSV and TSV export for spreadsheets and analysis tools • High-resolution PNG charts for lab reports • Complete project files for sharing with classmates or colleagues • Copy data to clipboard with a swipe and continue in Sheets or Excel with errors in place **DESIGNED FOR LAB WORK** σT adapts to your device: • iPhone: Full-featured portable lab companion • iPad: Side-by-side layout for efficient data entry • Mac: Native desktop experience via Catalyst **YOUR DATA, YOUR DEVICE** All measurements are stored locally. No account required, no cloud sync, no tracking. σT works completely offline.