Download LVDT - Newmark Structural Engineering Laboratory

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A requirement
mayexistwheremultipleLPG2000S
areto b€ usedandwhereunjlsorwiringwillbe locatedin closeproximity
theoscillators
of multipleunitsto preventcrossblk,beating,andinternodulation
eaci other.TheLPC-2000cansynchronize
betweenunib. To synchronize
the oscillators,
connecitogetherterminal5 on all unitsandconnectbgetherterminal10onallunits.
Theseconnections
are j!3gdi!9!..1ptheconnedionsshownon page3. Oneunitshouldbe designatedasthe"Mastefandthe
'Slaves'.
withthe insttuctions
balanceof the unitsdesignatedas
The'Mastef unifsexciiationfrequencymustbe sd in acco{dance
givenintheparagraph
"Excitation
Frequency
entitled
Seledion'.
Onthe'Masteiunit,movejumperlrom58 to 59. 'Slave"units
(shortng
ffom51,52, 53 and59.
musthaveajump€r(shorting
bar)on 58 andalljumpers
bars)mustberemoved
LPG-zO0 Slave l:l
Additional Connections For IPC-2000 Mult'rchannel
eMaster/Slave" Confi guration
GALIBRATION PROCEDURE(Voltage
Output)
jumperbetween
7 andI
Tocalibrate,
remove
LVDTsecondary
wire,usuallyRedo. (A)fromterminal
9. Inserttemporary
te.minals
(thisjumper
power
Adjusttheze.o
wjllberemoved
afierZeroadjustrnent).
ApplyAC
tgunitand
allowa 15 minute
wannup.
jumperfrom
controluntilan outputof 0 V DCis obtainedb€tveenterminals4 and5. De-energize
unitandremovetemporary
between
teminals7 and9. Re-connect
secondarywire
Redor (A)to terminal9,Applypowerto unitandmoveLVDTcoreor
pointfromwhich
thereference
bodyunlilanoutputof 0V DCis obtained.
Thisposition
isthetruenullofthesensorand
subseouent
oosition
measurements
aremade.
makethisadjustrnent
as closeas
NOTElf rnechanical
adjustment
of thecorcor LVDTbodyis difiicultor impossible,
possibleandthenadjusttheZerocontrolto obtain0 V OCoutput.lt is importantthatthe LVDTbewithin5oloof its kue nullposition
is withintheLVOTS
ratedlinearrange.Offsetsof morethan5%mayresultin non-linearresultsat
to ensurethatfull displacement
or neaafullscaledisglacem€nt.
Movethe LVDTcoreto its full scaledisplacement
andadjustthe Spancontrolto obiaina readingof 10V DC. Outputsof lessthan
bySpan
10V DCmaybeobtained
theSpancontol(e.9.5VDC).lfdesi.edfullscaleoutputcannotbeobtiained
byadjusljng
tableonpage
control
adjustment,
resetgainjumpers(shorting
bars)to nexthigheror lowersettingasshownin'GAINSELECTION"
to resetgainjumpers.Ecsg!el9-de=!!e!g!29-q!!
5 andthenreadjustSpanconkolto obtaindesiredoutput.lf it is necessary
Drioato removinocover.
Unitis nowreadyfor normaloperation.
GALIBRATION FOR 10O% ZERO OFFSET (Voltageoutput)
100%zerooflsetallowsthe userto obiaina unipolaroutputoverthefullrangeof theLVDT.
PROCEDURE"
section
fortullscaleuse,butadjusttheSpancontrolfor
inthe'CALIBRATION
Followtheinsfudionsasdescdbed
andadjusttheZerocontrol
halfthedesired
fullscaleoutput(e.g.5 V DC).MovetheLVDTcoreto'minLE'tullscaledisplacement
fordesired
tullscaleoutput.
andadjusttheSpancontrol
to obtainzerooutput.MovetheLVDTcoreto'plus"tullscaledisplacement
Repeat
thisprocedure
to ensurepropercalibration.
Unitis nowreadyfor unipolar
operation.
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