Tus neeg siv phau ntawv

4.9X-YOperation

SettheTIME/DIVswitchtoX-Yposition.Thentheinstrumentworksasan

X-Yoscilloscope.Eachinputisappliedtotheinstrumentasfollows.

X-axissignal(horizontalaxissignal):CH1INPUT.

Y-axissignal(verticalaxissignal):CH2INPUT.

Note:WhenhighfrequencysignalsaredisplayedintheX-Yoperation,pay

attentiontothefrequencybandwidthsandphasedifferencebetweenXandY-axis.

X-Yoperationpermitstheoscilloscopetoperformmanymeasurementsnotpossiblewithconventionalsweepoperation.The

CRTdisplaybecomesanelectronicgraphoftwoinstantaneousvoltages.Thedisplaymaybeadirectcomparisonofthetwo

voltagessuchasavectorscopedisplayofvideocolorbarpatterns.However,theX-Ymodecanbeusedtographalmostany

dynamiccharacteristicifatransducerisusedtochangethecharacteristic(frequency,temperature,velocity,etc.)intoavoltage.

Onecommonapplicationisfrequencyresponsemeasurements,wheretheY-axiscorrespondstosignalamplitudeandtheX-axis

correspondstofrequency.

1.SettheTIME/DIVcontroltotheX-Yposition(fullycounterclockwise).Inthismode,channel1becomestheX-axis

Inputandchannel2becomestheY-axisinput.

2.TheXandYpositionsarenowadjustedusingthehorizontalPOSITIONandC2POSITIONcontrols

respectively.

3.Adjusttheamountofvertical(Y-axis)deflectionwiththeCH2VOLTS/DIVandVARcontrols.

4.Adjusttheamountofhorizontal(X-axis)deflectionwiththeCH1VOLTS/DIVandVARcontrols.

Yaxi s( CH2)

Xaxi s

( CH1)

Figure4-8

4.10 CalibrationofProbe

Asexplainedpreviously,theprobemakesupawiderangeattenuator.Unlessphasecompensationisproperlydone,the

displayedwaveformisdistortedcausingmeasurementerrors.Therefore,theprobemustbeproperlycompensatedbeforeuse.

Connectthel0:lprobeBNCtotheINPUTterminalofCH1orCH2andsetVOLTS/DIVswitchat50mV.Connectthe

Probetiptothecalibrationvoltageoutputterminalandadjustthecompensationtrimmeronprobeforoptimumsquarewave

(minimumovershoot,roundingoffandtilt).

Figure4-9

(a)Correctcompensation(b)Overcompensation

(c)Insufficientcompensation

4.11DCBALAdjustments

TheATTbalanceoftheverticalaxiscanbemadeeasily.

(1)SettheinputcouplingswitchesofCH1andCH2toGNDandsettheTRIGMODEtoAUTO.Thenpositionthe

Baselinetothecenter.

(2)TurntheVLOTS/DIVswitchto5mV-10mVandadjustsothatthelinedoesnotmove.