SI Unit Symbols in UTF-8 — Look-Alike Codepoints (.csv)
Eight measurements whose unit symbols use the codepoints that have Unicode look-alikes: MICRO SIGN against GREEK MU, OHM SIGN against GREEK OMEGA, ANGSTROM SIGN against A-with-ring. Each row also carries an ASCII fallback, so a normalisation bug shows up as a column mismatch rather than as an invisible change.
quantity,symbol,unit_symbol,unit_ascii,value,note
length,l,µm,um,5.2,MICRO SIGN U+00B5 versus GREEK MU U+03BC
resistance,R,Ω,ohm,47.5,OHM SIGN U+2126 versus GREEK OMEGA U+03A9
temperature,T,°C,degC,21.4,DEGREE SIGN U+00B0 then C
wavelength,λ,Å,angstrom,5891.0,ANGSTROM SIGN U+212B versus A WITH RING U+00C5
mass fraction,w,‰,per_mille,3.5,PER MILLE SIGN U+2030
uncertainty,u,±,+/-,0.2,PLUS-MINUS SIGN U+00B1
angle,θ,″,arcsec,12.0,"DOUBLE PRIME U+2033, not a quote character"
energy,E,J·mol⁻¹,J/mol,412.6,MIDDLE DOT and SUPERSCRIPT MINUS ONE
Specifications
- Rows
- 8
- Columns
- 6
- Encoding
- UTF-8 without BOM
- Line Endings
- LF
- Look Alike Pairs
- micro/mu, ohm/omega, angstrom/A-ring
- Ascii Fallback Column
- unit_ascii
- Normalisation Note
- NFKC folds several of these onto their Greek equivalents
Testing contract
Expected to pass- Scenario
- Read the file as UTF-8 and compare each unit_symbol against its exact expected codepoint before and after NFKC normalisation.
- Expected result
- µ reads as U+00B5 and Ω as U+2126 in the raw file, NFKC folds them to U+03BC and U+03A9, and every row still maps to its unit_ascii fallback afterwards.
What is a .csv file?
CSV (Comma-Separated Values) is a plain-text tabular format where rows are lines and fields are separated by commas, with quoting rules for values that contain delimiters, quotes, or newlines. It has no formal type system and depends on encoding and dialect conventions. It is the most portable format for tabular data exchange.
How to use this file
Use an example CSV to test parsers against quoting and embedded-delimiter edge cases, header handling, encoding detection, and import pipelines into databases or spreadsheets.
How to use this file for testing
“SI Unit Symbols in UTF-8 — Look-Alike Codepoints (.csv)” is a deterministic Novus Examples fixture for Scientific data, Encoding detection, Editor testing. Citation catalogs (BibTeX, RIS), chemistry structures (MDL Molfile, PDB), and gridded binary data (NetCDF, FITS) — for testing reference managers, molecule viewers, and scientific-data loaders.
Documented properties for this file: 8 rows · 6 columns · UTF-8 without BOM · LF. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
Scientific fixtures are small, valid, and fully synthetic — no real organism, patient, sample, or observation. Point your parser or loader at the file and check it reads the documented records, variables, or headers; binary formats ship a readable twin or metadata listing for comparison.
Code examples
import pandas as pd
df = pd.read_csv("si-unit-symbols-utf8.csv")
print(df.head())
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