Measuring Electrical Parameters; Input Impedance; Ranges; Measuring A Composite Signal - Fluke ProcessMeter 787 User Manual

Measuring Electrical Parameters

The proper sequence for taking measurements is as
follows:
1. Plug the test leads into the appropriate jacks.
2. Set the rotary knob.
3. Touch the probes to the test points.

Input Impedance

For the voltage measurement functions, input impedance
is 10 M . See the specifications for more information.

Ranges

A measurement range determines the highest value the
meter can measure. Most meter measurement functions
have more than one range (see the Specifications).
Being in the right range is important:
If the range is too low, the display shows OL
(overload).
If the range is too high, the meter will not be
displaying its most accurate measurement .
Measuring Electrical Parameters
The meter normally automatically selects the lowest
range that will measure the applied input signal (Auto
showing on the display). Press
the range. Each time you press
selects the next higher range.
If you have locked the range, the meter resumes auto
ranging when you change to another measurement
function or you press

Measuring a Composite Signal

Because the input is dc-coupled, to meaure an ac voltage
or frequency with a dc bias, you must manually select the
range specified in Table 7. For example, to measure 100
mV ac with 20 V dc superimposed, select the 4 V range.
Table 7. Range Requirements for Measuring a
Composite Signal
Range (ac)
400.0 mV
4.000 V
40.00 V
400.0 V
1000 V
ProcessMeter
if you want to lock
, the meter
and hold it for 1 second.
Max. Allowable AC + DC
3 V
30 V
300 V
400 V
1000 V
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