Fluke 787 user manual Simulate Mode, Changing the Current Span

Models: 787

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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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Fluke 787 user manual Simulate Mode, Changing the Current Span