Fluke 787 [26/50] Simulate mode

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

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.

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%

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.