This standard BS ISO 3454:2008 Hydrometry. Direct depth sounding and suspension equipment is classified in these ICS categories:
17.120.20 Flow in open channels
This International Standard specifies the functional requirements of the equipment, excluding bankside cableway systems, used in the measurement of liquid flow in open channels for
sounding (by direct method), and
suspending the measuring equipment (for example, current-meter or sediment sampler) at the point of measurement.