ISO 22013:2021

This document defines terms, specifies test methods and provides reporting requirements for marine sensor specifications to ensure a consistent reporting by manufacturers.
It is applicable to those devices known as conductivity-temperature-depth (CTDs), sound velocity probes, multi-parameter sondes and dissolved gas sensors, that measure parameters such as conductivity, temperature, pressure, sound speed, dissolved oxygen, turbidity, pH, and chlorophyll in seawater.
It is also generally applicable to all marine environment instruments.
NOTE 1: A 'CTD' directly measures conductivity, temperature, and pressure. Depth is derived from pressure using an equation.
NOTE 2: The term sound velocity probe is widely used to describe instruments that measure sound speed. In this document the term 'sound velocity' is used when describing the type of sensor, and the term 'sound speed' is used when describing the parameter or measurand, but these terms can be used interchangeably.