Doc Extraction Unit Detection And Normalization

Unit Detection and Normalization (+4)

Unit Detection and Normalization

Recognize units in parentheses, brackets, or inline: (m/s²), [ksi], N/mm². Normalize to a canonical form:

Flag SI vs imperial vs field units. Prefer SI in output; keep original as units_original.

Standards Reference Parsing

Parse references like DNV-RP-B401 Section 3.4.6 into structured form:

standard_ref:
  body: DNV
  document: RP-B401
  edition: null         # null unless explicitly stated in source text
  edition_inferred: 2021  # set only when edition can be inferred; null otherwise
  section: 3.4.6
  table: null
  figure: null
  raw: "DNV-RP-B401 Section 3.4.6"

Inference rule: edition must be null unless the source text explicitly states the year. Use edition_inferred only when surrounding context (title page, header, or adjacent reference) provides strong evidence; never guess.

Common patterns:

• DNV-RP-XXXX Sec N.N.N / Section N.N / Table N-N / Figure N-N
• API RP NNX Section N / API 579-1 Part N
• ASME BPVC Section VIII Div 2
• ISO NNNNN-N:YYYY Clause N.N

Safety and Design Factor Identification

Flag values tagged as safety factors, design factors, or usage factors:

• Keywords: "safety factor", "design factor", "utilisation factor", "usage factor"
• Often dimensionless ratios between 0 and 10
• Extract: {name, value, standard_ref, applicability}

Material Property Recognition

Detect material properties in text or tables:

• Yield strength (SMYS), tensile strength (SMTS), Young's modulus
• Density, thermal expansion coefficient, Poisson's ratio
• Fatigue S-N curve parameters
• Extract: {property, value, units, material_grade, temperature, standard_ref}

Condition and Applicability Tagging

Many values have applicability constraints. Tag extracted items with:

• Temperature range
• Depth/pressure range
• Material grade or category
• Environmental condition (seawater, air, buried)
• Service life assumptions