Overview
ISO 7168-1:1999 - "Air quality - Exchange of data - Part 1: General data format" defines a human- and machine‑readable file format for exchanging air quality and related metadata. The standard specifies a consistent structure, mandatory and optional keywords/level descriptors, character encoding and line rules to ensure interoperable transmission of monitoring data between organisations and automated systems (for example, spreadsheet import or database ingestion).
Key topics and technical requirements
- Hierarchical file structure: data are organised into groups → blocks → records → datum, allowing clear separation of identification, network, site, measurand and data groups.
- Keywords and level descriptors: every piece of information is tied to a defined keyword (see Table 1 in the standard) so files are self‑describing and unambiguous.
- Character set and encoding: files must use the ISO/IEC 646 (7‑bit) coded character set; national characters are not permitted (Annex A normative).
- Line and syntax rules:
- Each keyword/level descriptor starts on a new line; maximum line length is 255 characters (including RNL).
- End‑of‑line uses a Return‑to‑New‑Line (RNL) sequence: Line Feed + Carriage Return (decimal 10 and 13) for cross‑platform readability.
- Keyword separator uses the combination "=;" (equal sign followed by the data separator).
- Multiple data values are separated by a semicolon (;).
- Comments are enclosed in curly braces { }; text fields use quotation marks (decimal 34).
- Files are case‑insensitive.
- Data formats and units: the standard mandates formats for time, numerical values, country codes and geolocation (references include ISO 3166‑1 and ISO 6709). Annex B provides measurand codes and Annex C covers latitude/longitude/altitude presentation (both normative).
- Mandatory vs optional fields: ISO 7168-1 lists required fields (e.g., file_name, file_creation_date, site_latitude/longitude, measurand_code) and many optional descriptors for richer metadata (measurement method, calibration, site characterization).
Practical applications and users
Who benefits:
- Environmental agencies and air quality networks exchanging monitoring results across jurisdictions.
- Data suppliers and laboratories standardising exports for regulatory reporting.
- Software developers and vendors building ingestion tools, dashboards or converters (spreadsheets, databases, GIS).
- Researchers and consultants aggregating multi‑source datasets for analysis, modelling and compliance checks.
Common uses:
- Interoperable data exchange between monitoring networks.
- Direct import into spreadsheets or automated processing pipelines.
- Archival of measurement datasets with self‑describing metadata to support QA/QC and long‑term analyses.
- Harmonised reporting for cross‑border air quality assessments.
Related standards
Keywords: ISO 7168-1, air quality data format, exchange of data, measurand codes, file format, environmental monitoring, data interoperability, latitude longitude format.
