12
Digital Ground Resistance Tester Model 3640 and 4610
3.5 Auto-ranging
Theselectionofthemeasurementcurrentisdependingontheresistance
tomeasure.
WhentheinstrumentisturnedON,themeasurementstartsonthesmallest
currentrange(100µA).Ifthemeasurementisbetween185and1950cts,
therangestaysthesame(100µA).Ifthemeasurementisunder185cts,
thecurrentismultipliedby10(within10mAmax).Ifitisabove1950cts,the
currentisdividedby10(withoutgoingunder100µA).
Thisisdonetoavoidswitchingbackandforthbetweenrangeswhenyou
aremeasuring190Ω.Itispossibletodisplay190.0or190Ωdependingon
theautomaticrangeselection.