Manual Ranging And Auto Ranging; Ac Zero Input Behavior Of True Rms Meters; Vfd Low-Pass Filter (All 1587 Models) - Fluke 1587 FC User Manual

Manual Ranging and Auto Ranging

The Meter has both Manual Range and Auto Range
modes.
•
In the Auto Range mode, the Meter selects the range
with the best resolution.
•
In the Manual Range mode, you override Auto Range
and select the range yourself.
When you turn the Meter on, it defaults to Auto Range and
Auto Range is shown.
1. To enter the Manual Range mode, press r.
Manual Range is shown.
2. In the Manual Range mode, press r to increment
the range. After the highest range, the Meter wraps to
the lowest range.
You cannot manually change the range in the MIN
MAX AVG, or Display HOLD modes.
If you press r while in MIN MAX AVG, or
Display HOLD the Meter beeps twice, indicating
an invalid operation and the range does not
change.
3. To exit Manual Range, press r for one second or
turn the rotary switch. The Meter returns to Auto
Range and Auto Range is shown.
Note
Manual Ranging and Auto Ranging
AC Zero Input Behavior of True RMS
Meters
True RMS Meters accurately measure distorted
waveforms, but when the input leads are shorted together
in the AC functions, the Meter displays a residual reading
between 1 and 30 counts. When the test leads are open,
the display readings may fluctuate due to interference.
These offset readings are normal. They do not affect the
Meter's ac measurement accuracy over the specified
measurement ranges.
Unspecified input levels are:
•
AC voltage: below 5 % of 600 mV ac, or 30 mV ac.
•
AC current: below 5 % of 60 mA ac, or 3 mA ac.

VFD Low-Pass Filter (all 1587 Models)

The 1587 is equipped with an ac low-pass filter to measure
the output of variable frequency motor drives (VFD). For
ac voltage or ac frequency (B) measurements, press the
blue button to activate the Low-Pass Filter function (K).
The Meter continues measuring in the selected ac mode,
but now the signal diverts through a filter that blocks
unwanted frequencies above 800 Hz. Refer to Figure 1.
The low pass filter can improve measurement performance
on composite sine waves that are typically generated by
inverters and variable frequency motor drives.
Insulation Multimeter
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