EXTECH MA140 [10/21] Ac and dc voltage measurements

MA44x‐en‐GB_V1.08/16

ACandDCVoltageMeasurements

WARNING:Donotapply>600VAC/DCbetweenthemeterterminalsandground.

CAUTION:Whenconnectingthetestleadstothecircuitordeviceundertest,connect

theblackleadbeforetheredlead;whenremovingthetestleads,removetheredleadbefore

theblacklead.

1. SetthefunctionselectswitchtotheVoltageposition .

2. UsetheM(Mode)buttontoselectACorDCVoltage.

3. Inserttheblacktestleadbananaplugintothenegative(COM)jackandtheredtestlead

bananaplugintothepositive(V)jack.

4. Touchthetestprobetipstothecircuitorundertest.For

DCmeasurementsintherange

of400mV,usetheRelativemodetozerothedisplaybeforetakingameasurement.

5. ReadthevoltageintheLCD.Thedisplaywillindicatetheproperdecimalpointandvalue.

6. Relative(REL)modecanbeusedtosetareferencereadingfromwhich

subsequent

readingswillbeoffset(referencereading–actualreading=displayedreading).Long

presstheRELbuttontoactivate/deactivatetherelativemode.

7. TheMA440candisplaythefrequency(Hz)ordutycycle(%)ofthemeasuredvoltage.

ShortpresstheHz%buttontotogglefrequencyandduty

cyclereadings.Forthe

MA443/MA445seethededicationsectiononFrequencyforfrequencyanddutycycle.

8. TheMA443andMA445recordMAXandMINreadings.ShortpresstheMAXMINbutton

tostepthroughtheMAXMINreadings.LongpresstheMAXMINbuttontoexit.

9. Shortpress

theHbuttontofreeze/unfreezethedisplayedreading.Longpressto

activate/deactivatethedisplaybacklight.

NOTES:TheMA440displaysOLwhentheinputexceeds1000V.TheMA443/MA445display

whenthetestedvoltageis>30Vandsoundsthebuzzerwhenthevoltageinputis>600V. 







Fig.5MA443/MA445VoltagetestFig.6–MA440Voltagetesting