The toUnit on a UnitConversion is typically the canonical unit for the analyte or the unit required by the regulatory threshold. After piper multiplies an incoming result value by the factor, it stores the result in toUnit. This ensures that all AnalyticalResult values in the database use a consistent unit, making trend analysis and threshold comparisons accurate across lab reports that may have used different units for the same chemical and matrix.
Technical section
Data model, API, and internals — visible to developers.