Data Sheet

11
MEASURING METHOD AND OTHER CHARACTERISTICS
True RMS AC Current
Measurement Method Direct coupled to the fuse and shunt; AC-coupled True RMS measurement
(Measure the AC component only).
Crest Factor ≤3atfullrange
Max. Input DC+ACcurrentpeakvalue<300 %ofrange.
The RMS current < 10 A rms including the DC component.
Shunt Resistor 100Ωfor200uA,2mA
1Ωfor20mA,200mA
0.01Ωfor2A,10A
Input Protection Externally accessible 500 mA, 250 V fast blow fuse
Internal 12 A, 250 V slow blow fuse
Settling Time Considerations
Thedefaultmeasurementdelayisselectedtogivethecorrectreadingformostmeasurements.MakesuretheRCcircuitofthe
inputterminalhasfullysettled(about1s)beforetakinghigheraccuracymeasurements.
Applying > 300 Vrms (or > 5 Arms) will cause self-heating of signal-conditioning components and these error are included in the
instrumentspecications.Internaltemperaturechangesduetoself-heatingmaycauseadditionalerroronloweracvoltageranges.
Theadditionalerrorwillbelowerthan0.02 %ofreadingandwillgenerallydissipatewithinafewminutesasthesignal-conditioning
components return to normal operating temperature.
Frequency and Period
Measurement Method Reciprocal-counting technique, AC-coupled input using the AC voltage function.
Input Impedance 1MΩ±2%inparallelwith<150pFcapacitanceonanyrange
Input Protection 750 V rms on all ranges
Measurement Considerations All frequency counters are susceptible to error when measuring low-voltage,
low-frequency signals. Shielding inputs from external noise is recommended.
Settling Time Considerations Errors will occur when attempting to measure the frequency or period of an input following
adcoffsetvoltagechange.MakesuretheRCinputcircuitattheinputterminalshasfully
settled(about1s)beforemakingaccuratemeasurements.
Capacitance Measurement
Measurement Method Apply constant current into the capacitance, and measure the rate of voltage change.
Connection Type 2-wire
Input Protection 1000 V on all ranges
Measurement considerations Since small capacitance measurements are susceptible to the external noise, shielding
inputsfromexternalnoisepickupiscriticalforminimizingmeasurementerrors.
Temperature Measurement
Measurement Method Support for TC and RTD types of sensor
Measurement considerations Thebuilt-incoldjunctiontemperaturetracksthetemperatureinsidethebananajack.
Thechangeofthetemperatureinthebananajackmaycauseadditionalerror.Whenusing
the built-in cold junction compensation, connect the sensor terminal of the thermocouple
tothebananajackandallowittowarmupforatleast3minutestominimizeerrors.