Error handling

A measurement application benefits from knowing which layer failed. An ADC communication error is not the same as a valid resistance that falls outside an RTD model's range.

rtd-sensor therefore keeps its package-owned RTD exceptions small and does not translate arbitrary acquisition failures into model errors.

Public exception taxonomy available since: rtd-sensor 0.5.0. Portable-model and calibration-fitting exceptions were added in 0.6.0.

Catch a specific conversion problem

from rtd_sensor import exceptions, pt100

try:
    temperature_c = pt100.resistance_to_celsius(measured_resistance)
except exceptions.RTDOutOfRangeError:
    # Resistance was supplied, but it is outside this RTD model's range.
    ...

Catch package-owned RTD domain failures

from rtd_sensor import exceptions

try:
    ...
except exceptions.RTDError as exc:
    ...

Use this when your application wants one branch for package-owned RTD domain errors without also catching unrelated hardware exceptions.

Public exception roles

Exception	Typical meaning
`RTDOutOfRangeError`	Temperature or resistance lies outside a model's supported range
`UnknownRTDModelError`	Unknown canonical built-in model ID
`InvalidRTDModelError`	Custom model definition fails scientific/numerical validation
`InvalidPortableModelDefinitionError`	Portable artifact is malformed, unsupported, or invalid
`RTDFitError`	Calibration fit cannot produce an acceptable model
`RTDModelSelectionError`	Conflicting or unsupported model-selection declarations

Several retain compatibility with conventional Python exception families: for example, package-owned model/range/fitting errors that historically behaved as value problems remain compatible with ValueError, while unknown model IDs are compatible with KeyError.

Invalid scalar input

Not every bad scalar is an RTD domain exception. Non-finite or wrong-type inputs may raise ValueError or TypeError according to the public API. Boolean physical values are explicitly rejected.

Acquisition exceptions remain acquisition exceptions

from rtd_sensor import measurement, pt100

# If hardware_reader.read_resistance_ohms() raises a driver-specific SPI error,
# that error propagates. It is not converted into RTDOutOfRangeError.
temperature_c = measurement.read_temperature_celsius(
    hardware_reader,
    model=pt100,
)

This allows the application to distinguish “could not acquire resistance” from “acquired resistance does not fit the selected model.”