Ac Voltage - Fluke 8508A User Manual

8508A
Users Manual
Internal Guard Connections
External Guard
isolated from each other and from any internal connection. The internal guard shields and
tracks are connected directly to the internal 0V.
External Guard
internal 0V, and connected to the
Ohms Guard:
provide an Ohms Guard. In these cases the internal guard shields, tracks and selected
front or rear Guard terminal are connected to the internal 0V.
The simplified diagram in Figure 3-4 illustrates the switching arrangement.
Selecting External Guard (ExGd)
See Figure 3-3 for a description of External Guard Connections.
To select
1. Press
2. Press the menu key ExGd to toggle the Multimeter's Guarding options.
The ExGd annunciator on the left-hand display indicates that External Guarding is
selected.

AC Voltage

Press the


3-8
not selected: The Guard terminals on the front and rear panels are
selected: The internal guard shields and tracks are disconnected from the
In the Ohms or PRT Functions the External Guard selection is modified to
Guard terminal front
External Guard
Internal Guard and External Guard
(OHMS and PRT)
Figure 3-4. Internal Guard Connections
:
External Guard
to enter the
Input key
key to see the
ACV
This function provides both 2-wire and 4-wire measurements, in decade

ranges from 200mV to 200V and a 1kV range.
To cancel autoranging and enter a manually selected range, press any range

selection or the Auto softkey. The Multimeter enters the selected range or
reverts to the auto-selected range.
terminal of the selected front or rear input.
Guard
Guard terminal rear
Front Rear
Internal Guard
External Guard
(DCV & I, ACV & I)
0 V
menu.
INPUT
INPUT Menu
menu.
ACV
ACV Menu
Internal Guard
Shield and Tracks
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