Overview
ISO 22804:2023 - Marine technology - General technical requirement of marine conductivity-temperature-depth (CTD) measuring instrument - defines core technical requirements and test methods for CTD profilers used in ocean observation. The standard ensures consistent reporting on testing, inspection rules, marking, packaging, transportation and storage for CTD instruments used in fixed‑point and mobile marine observation platforms, including shipborne systems. It covers direct measurements of conductivity, temperature and pressure (with depth derived from pressure), and supports both EOS‑80 and TEOS‑10 salinity algorithms in user software.
Key topics and technical requirements
- Scope and applicability: Applies to marine fixed‑point and mobile observation, monitoring platforms and shipborne CTD instruments.
- Instrument classification: Defines three performance levels (grades) based on temperature, conductivity and pressure measurement capability to aid selection and testing.
- Measuring performance: Requirements for accuracy, resolution and stability of temperature, conductivity and pressure sensors.
- Environmental adaptability: Tests and criteria for temperature, humidity, vibration, shock and pressure endurance (references IEC environmental test methods).
- Appearance and identification: Cosmetic requirements, product identification, nameplate and fastening specifications.
- Interface and data format: Standardized interface checks and recommended data formats to ensure interoperability and reliable data exchange.
- Test methods: Procedures for instrumentation, appearance inspection, performance testing (accuracy tests, resolution, stability) and environmental testing.
- Marking, packaging, transport and storage: Labeling, packaging requirements, transport handling and storage environment specifications to protect instruments in marine supply chains.
- User software: Requirements for measurement management, parameter calculation (support for EOS‑80 and TEOS‑10), data processing and record keeping.
- Informative annexes: Example record tables for accuracy tests, practical salinity calculations and pressure‑to‑depth conversion formulae.
Applications and users
ISO 22804:2023 is essential for:
- CTD manufacturers designing, testing and certifying instruments for marine research and monitoring.
- Oceanographic institutes and laboratories validating instrument performance and acceptance testing.
- Ship operators, environmental monitoring agencies and offshore platforms deploying CTD sensors for temperature, salinity and depth profiling.
- Calibration and test houses performing compliance and environmental testing.
Adopting this standard helps ensure reliable CTD data for climate research, oceanography, ecosystem monitoring and maritime operations.
Related standards
ISO 22804 references and aligns with IEC environmental testing standards (IEC 60068 series) and ISO 21173 (submersible hydrostatic pressure testing). These related documents inform environmental and pressure‑related test methods for marine instrumentation.