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Model 4277A
SECTION III
@
TRIGGER Keys:
These keys select the
trigger mode for
triggering
measurement
(Internal
or
Manual/External):
INT:
Internal
trigger
signal
enables instrument to make
repeated automatic measure¬
ments.
MAN/EXT:
Measurement
is
triggered
each
time
this
key
is
pressed.
Measurement data
is held until the next time
the key is pressed. Or in this
mode
measurement
is
triggered
by
an
external
trigger signal applied to the
rear
panel
EXT
TRIGGER
connector ((4)in Figure 3-2).
(g) TEST
SIGNAL
LEVEL
Selector Key and
Indicators;
This key selects two test signal levels
;
HIGH and LOW. HIGH level is IVrms and
LOW level is 20mVrms.
The selected test
signal
level
is
indicated
by
the
corresponding LED lamp.
@ fvlEASUREMENT
SPEED
Select Key and
Indicators:
This key selects three measurement speeds:
SLOW,
MEDIUM
or
FAST.
Actual
measurement
speed
depends
on
test
frequency, LC [ Z I
range (^, DISPLAY A
Function (fs), and the value of the device
under
test.
The
selected
measurement
speed
mode
is
indicated
by
the
corresponding LED lamp.
SLOW :
Measurement
speed
is
approxi¬
mately
1/4
that
of
medium
measurement speed.
MED;
Measurement
speed
is
approxi¬
mately
14
measurements
per
second in C-G measurement mode.
FAST;
Measurement
speed
is
approxi¬
mately one and a half that of
medium measurement speed.
DISPLAY
B
Function
Select
Key
and
Indicators:
This key,
@ , selects the
measurement
parameter for display on DISPLAY B (6).
The selected parameter is indicated by the
corresponding LED lamp. Pressing this key
shifts
the
selected
parameter
in
a
top-to-bottom
sequence.
Selectable
parameters are as follows:
D:
Measures the dissipation factor of
the DUT.
DISPLAY A Function
(r|) must be set to L (inductance)
or C (capacitance).
Q;
Measures the quality factor of the
DUT.
DISPLAY A Function
@
must be set to L (inductance) or C
(capacitance).
Q
values
are
calculated
as
the
reciprocal
dissipation factor.
ESR/G: Measures
the
equivalent
series
resistance or conductance of the
DUT.
DISPLAY A Function
@
must be set to L (inductance) or C
(capacitance).
ESR
is
selected
when CIRCUIT MODE @ is set to
G
is
^ected
when
CIRCUIT
MODE
@
is
set
to
(16) LC I Z I
RANGE
Selector
Keys
and
Indicator:
These keys select the measurement range
and
the ranging method for inductance,
capacitance and impedance measurements.
AUTO (when indicator is lit):
Optimum range for the DUT's value is
automatically selected.
MANUAL (when indicator is not lit);
Measurement range is fixed (even when
the DUT is changed). Manual ranging is
done by pressing the adjacent DOWN
( @ ) or UP ( H]) key.
Note
Pressing the DOWN or UP key sets
the ranging mode to MANUAL even
if the ranging mode was initially set
to AUTO.
Figure 3-1. Front Panel Features (Sheet 4 of 6).
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