Lab reports may express concentrations in different units than the regulatory thresholds they are compared against — a lab might report in ug/L while a threshold is set in mg/L. UnitConversion records let piper normalize these values automatically. Each record specifies a fromUnit, a toUnit, a numeric factor (the multiplier applied to convert the value), and a matrix so that conversions specific to groundwater behave differently from soil conversions when the same units have different implications in different media.
Technical section
Data model, API, and internals — visible to developers.