Fluke 787 user manual Simulate Mode, Changing the Current Span

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787

Users Manual

Simulate Mode

Simulate mode is so named because the meter simulates a current loop transmitter. Use simulate mode when an external dc voltage of 24 to 30V is in series with the current loop under test.

Caution

Changing the Current Span

The meter’s current output span has two settings (with overrange to 24 mA):

4 mA = 0%, 20 mA = 100% (factory default)

0 mA = 0%, 20 mA = 100%

Set the rotary switch to one of the mA output settings BEFORE you connect the test leads to a current loop. Otherwise, a low impedance from the other rotary switch positions could be presented to the loop, causing up to 50 mA to flow in the loop.

Simulate mode is selected automatically by inserting the test leads into the SIMULATE + and jacks as shown in Figure 8. Simulate mode conserves battery life, so use it instead of source mode whenever possible.

The display looks the same in source and simulate modes. The way to tell which mode is in use is to see which pair of output jacks is in use.

To find out which span is selected, short the OUTPUT SOURCE + and jacks, turn the rotary switch to OUTPUT [mA, and observe the 0% output level.

To toggle and save the current output span in nonvolatile memory (retained when the power is turned off):

1.Turn off the meter.

2.Hold down the Kpushbutton while you turn the rotary switch to OUTPUT [mA.

3.Wait at least 2 seconds, then release K.

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Contents 787 Limited Warranty & Limitation of Liability Table of Contents 787 IndexContacting Fluke Read Safety Information before you use the meterIntroduction Safety Information 787ProcessMeter International Symbols Meaning Symbol MeaningHow to Get Started Fluke 787 ProcessMeterGetting Acquainted with the Meter Input/Output JacksSimulate Transmitter Function Input/Output Jacks Measurement FunctionsSource Current Function Rotary Switch Positions for Measurements Functions Pushbutton ActionsRotary Switch Positions for mA Output Default Function Pushbuttons Pushbuttons FunctionsPushbutton CoarseElements of the Display Element Display MeaningDisplay Element MA, DC, mV, AC Or kΩ, kHz Auto 400100030 Input Impedance Measuring a Composite SignalMeasuring Electrical Parameters RangesTesting Diodes Displaying Minimum, Maximum, and AverageUsing TouchHold Compensating for Test Lead ResistanceUsing the Current Output Functions Source ModeSourcing Current Simulate Mode Changing the Current SpanSimulating a Transmitter Producing a Steady mA Output MA Output Adjust PushbuttonsAdjustment Manually Stepping the mA Output MA Stepping PushbuttonsMA Step Values Value for each span setting To 20 mA Auto Ramping the mA OutputPushbutton Default Power-Up OptionsPower-Up Options Action TakenMaintenance Battery LifeUsing the Holster and Flex-Stand General MaintenanceUsing the Holster and Flex-Stand Replacing the Battery Replacing the BatteryReplacing a Fuse If the Meter does not Work Replacing a FuseReplacement Parts and Accessories Fluke PN or Model no Replacement PartsDescription QuantityMP8 DC Volts Measurement SpecificationsResolution Range V dcAC Volts Measurement Range mV dc Resolution 400.0 Accuracy % of Reading + CountsDC Millivolts Measurement AC Current Measurement DC Current MeasurementMeasurement Current Range ResolutionOhms Measurement Input Range Minimum Sensitivity rms Sinewave 5 Hz to 5 kHz Frequency Counter AccuracyFrequency Counter Sensitivity Simulate Mode General SpecificationsSource mode Diode Test and Continuity TestCertifications CSA, UL, TÜV Index Knob positions, 9 Pushbuttons Loop supply, external Index 787