What phenomenon involving apparatus structure is an example of an environmental factor introducing instrumental uncertainty?

Answer

Thermal expansion or contraction due to temperature fluctuations

Changes in ambient conditions, such as temperature, can cause physical instruments to expand or contract, subtly altering their effective scale length and thus introducing an environmental factor directly into the instrumental uncertainty.

What phenomenon involving apparatus structure is an example of an environmental factor introducing instrumental uncertainty?
measurementmethodexperimentuncertaintyerror