ČSN EN ISO 20456
Měření průtoku tekutin v uzavřených profilech - Pokyn pro použití indukčních průtokoměrů pro vodivé kapaliny

ČSN EN IS 20459

This document applies to industrial electromagnetic flowmeters used for the measurement of flowrate of a conductive liquid in a closed conduit running full. It covers flowmeter types utilizing both alternating current (AC) and pulsed direct current (DC) circuits to drive the field coils and meters running from a mains power supply and those operating from batteries or other sources of power.
This document is not applicable to insertion-type flowmeters or electromagnetic flowmeters designed to work in open channels or pipes running partially full, nor does it apply to the measurement of magnetically permeable slurries or liquid metal applications.
This document does not specify safety requirements in relation to hazardous environmental usage of the flowmeter.