pt100-core

A small, platform-independent Python library for converting resistance measurements from a standard IEC 60751 Pt100 resistance temperature detector into temperature.

It also supports the inverse conversion from temperature to ideal Pt100 resistance for simulation and testing.

Scope

pt100-core handles:

Pt100 resistance in ohms ↔ temperature in Celsius

The initial implementation assumes:

• IEC 60751 Pt100
• 100 Ω at 0 °C
• α = 0.00385

The conversion is not specific to a particular sensor manufacturer.

Hardware-specific concerns such as ADC readings, GPIO, SPI, I²C, excitation circuits, and lead-wire compensation belong in separate hardware layers.

Basic usage

from rtd import pt100

temperature_c = pt100.resistance_to_celsius(119.3971)
resistance_ohms = pt100.celsius_to_resistance(50.0)

Development setup

The project currently targets Python 3.14.

conda create -n pt100-core python=3.14 pip
conda activate pt100-core
python -m pip install -e ".[dev]"

Run the checks:

pytest
ruff check .
mypy

Project structure

src/rtd/
    pt100.py
    simulation.py

tests/
docs/DESIGN.md

The repository is named pt100-core for discoverability. The Python package uses the broader rtd namespace so additional RTD families can be added later without changing existing Pt100 imports.

See docs/DESIGN.md for detailed architecture, mathematical assumptions, testing requirements, and future plans.

Status

Version 0.1.0 provides:

• IEC 60751 Pt100 resistance-to-temperature conversion
• temperature-to-resistance conversion
• input and supported-range validation
• independently sourced reference-value tests
• fixed, sequential, repeating, and noisy simulation readers
• reproducible seeded simulation noise
• a stable initial public API

License

This project is licensed under the Mozilla Public License 2.0. See LICENSE.