Table 5-02-05, add electromagnetic current meter

[amilan17]

Initial request

Missing Electromagnetic Current  Meter (ECM).

An ECM uses the Faraday principle of electromagnetic induction, which states that the water moving in a magnetic field will produce a voltage that is proportional to the velocity of the water. Insert an item with ECM in notations 364-369. It might be relevant to define sub-groups for mechanic, electromagnetic and acoustic devices.

Amendment details

notation	path	name	description
new		electromagnetic current meter	Determination of water current based on the principle that a conductor (water) moving through a magnetic field will produce an electrical current directly proportional to the speed of movement (Faraday’s law). By measuring this current and the resultant distortion in the magnetic field the instrument can be calibrated to determine point velocities of flowing water. [Based on Manual on Stream Gauging (WMO-No. 1044), Volume I. 2010]

Comments

No response

Requestor(s)

• Nicolas FELTZ, Service Public de Wallonie, Direction des Cours d'Eau non navigables, Belgium
• Emmanuel ROULIN, Institut Royal Météorologique de Belgique.

Stakeholder(s)

National Hydrological Services, WHOS

Publication(s)

Example: Manual on Codes (WMO-No. 306), Volume I.3, WMO Codes Registry, Code table 5-02-05, Measurement/observing method (terrestrial), http://codes.wmo.int/wmdr/ObservingMethodTerrestrial

Expected impact of change

MEDIUM

Collaborators

@amilan17, @jbianchi81, @disiiwash, @jkorhonen, José Valles, Paolo Leoni, Joao Carlos Carvalho (JET-HYDMON)

References

E.g., MacVicar, B.J., Beaulieu, E., Champagne, V. and Roy, A.G. (2007), Measuring water velocity in highly turbulent flows: field tests of an electromagnetic current meter (ECM) and an acoustic Doppler velocimeter (ADV). Earth Surf. Process. Landforms, 32: 1412-1432. https://doi.org/10.1002/esp.1497

Validation

No response

[amilan17]

https://github.com/wmo-im/tt-wigosmd/wiki/2022.11.03-TT-WISOSMD notes:

• need to create a "method" definition.

[jbianchi81]

From Paolo Leoni of WHOS experts group:

Into the "MANUAL ON STREAM GAUGING VOLUME I – FIELDWORK I" of WMO at page 84 there is a description of current meters of electromagnetic type.
https://library.wmo.int/doc_num.php?explnum_id=219

I would suggest you follow the definition of this method:

The Electromagnetic current meter method is based on the principle that a conductor (in this case, water) moving through a magnetic field will produce an electric current.

The velocity of the moving water can be related to the electric current produced and the distortion created in the magnetic field.

[jbianchi81]

And from the same source, page 78:

An electromagnetic current meter is based on the
principle that a conductor (water) moving through
a magnetic field will produce an electrical current
directly proportional to the speed of movement
(Faraday’s law). by measuring this current and the
resultant distortion in the magnetic field the
instrument can be calibrated to determine point
velocities of flowing water.

[jbianchi81]

updated proposal based on comments

[amilan17]

https://github.com/wmo-im/tt-wigosmd/wiki/2022.12.08-TT-WIGOSMD notes:
@gaochen-larc suggests shortening the definition.

[jbianchi81]

Thanks @amilan17 and @gaochen-larc . Could you please suggest which part of the definition to remove or shorten?

[amilan17]

https://github.com/wmo-im/tt-wigosmd/wiki/2023.01.12-TT-WIGOSMD notes:
the team has agreed to definition as is