Protocol
Keep the unit attached when moving the number
The number 500 is impressively precise about almost nothing on its own.
When it fits
- A value crosses a system boundary, report or manual calculation.
When to avoid it
- Currencies, temperature scales and business-specific units may need context beyond a simple multiplier. Do not improvise safety-critical conversions.
Why it matters
Carry the unit and the quantity definition with the value. Convert only after confirming that both sides measure the same kind of quantity. A correct conversion cannot repair a comparison between different business definitions.
Steps
- Record value, unit and what was measured together.
- Name the target unit and the documented conversion rule.
- Check one known example and preserve the original value for reconciliation.
An example
A duration of 500 milliseconds becomes 0.5 seconds, not 500 seconds. Separately confirm whether both systems include waiting time.
Check your result
The receiver can reconstruct the value's meaning and distinguish conversion from a changed measurement definition.
Keep this limit in mind
- Currencies, temperature scales and business-specific units may need context beyond a simple multiplier. Do not improvise safety-critical conversions.
Connected ideas
Useful withFind the first boundary where the record becomes wrong
Evidence and sources
Supports
UCUM distinguishes unit symbols, prefixes and semantic equivalence so numeric quantities can be interpreted with their units.
Compatible physical dimensions do not establish matching business definitions, measurement conditions or conversion dates.
The Unified Code for Units of Measure · Unit terms and semantic rules