FLOMAG 3000 - Installation and Operation Manual
5
Correct function ofthe magnetic
flowmeter requiresperfect
electricalconnection between
the sensor andtheadjacent
pipeline,grounding potential
and the power supplyprotective
wire.
For the flanged sensor withthe
adjacent conducting pipeline,
flangesshouldbe electrically
connectedandthepipeline
grounded.
Ifthe adjacent pipelineis
non-conductive, groundingrings
shouldbe inserted initor
equivalent method shouldbe
Fig.16: Grounding rings
Fig.17. The wafer sensor
Fig.18: Cathodicprotection
Fig.15: Grounding offlanges
connection ofsensor clamping
flangeswithgrounding point of
the sensor.
Ifelectriccurrent flowsthrough
the pipeline,e.g.for pipeline
cathodicprotectionagainst
corrosion, thesensorshouldbe
electricallyisolatedfromthe
adjacent pipeline. The sensor
shouldbe bridged over using a
wire andgalvanicisolationof
the flowmeter power supply
shouldbeprovided so thatthe
flowmeter canbeisolatedfrom
allother devices.
Sensor grounding
Selection of suitable sensor lining and electrode material
Linings
Sensorshaveanon-conductive
liningfromvariousmaterials.
Choice ofmaterialdepends on
measured fluid characteristics.
• Technical rubber
Technicalrubber issuitablefor
lowaggressivefluidswith
operationaltemperaturesfrom
0.1°Cto70°C. It fitsfor most
water management and sewage
treatment applications.Itis
manufactured intwovariants
“TG” –with hard structureand
“MG” –withsoftstructure.Soft
structure isusedfor fluidswith
higher contentofabrasive
particles(e.g.sand). Itisnot
suitable for drinking water.
• Resistant rubber
Type “NG” issuitable for
mediumaggressivefluidswith
operationaltemperaturesfrom
0.1 °C to 90°C. It can beused
for measurement ofhot service
water, condensate etc., aswell
asfordrinkingwater.If
temperature 100 °C canbe
exceeded,Teflon (PTFE) lining
isrecommended.
• Teflone or Hallar
Type “T” isthe mostuniversal
liningfor aggressivefluidswith
operationaltemperaturesfrom-
20 °Cto 150°C. It issuitable for
chemicaland food industry
applications.
Electrodes
Choiceofmaterialofmeasuring
electrodesalsodependson
measured fluid characteristics.
• Stainless steel – “Ss”
Standardelectrodesaremade
ofstainless steelAISI 316Ti.
Theyare suitablefor allusual
water basedfluidsandfor lower
concentrationsofacidsand
caustics.
• Hastelloy C-22 – “Ha”
For somespecialapplications,
materialofhigher qualityshould
beused. HastelloyC-276
electrodesarecharacterizedby
increased resistanceagainst
acidsand caustics and usually
aresuitableformostof
industrialapplications.
• Titanium - „Ti“
Suitablefor someacids,
lyes,chlorine, ureaand
sewage.
• Platinum –“Pt”
Forparticularlyaggressive
fluidslikeconcentratedacids
andcaustics,chemically
extremelyresistant material
shouldbechosen –platinum.
However,highcostofthis
materialisitsessential
drawback.
*Note –Wecan recommend
suitableliningand electrode
materialsforyour particular
application.
used to connectmeasuredfluid
electricalpotentialwithground.
For the wafer sensor, grounding
can be provided byelectrical
