IET Labs, Inc. RLC Digibridge 1693, Руководство пользователя и обслуживания, Страница: 137 / 171

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1693 RLC Digibridge
Service and Maintenance
3. Confirm or select the following measurement
conditions on the Digibridge:
[FUNCTION) - ENTER (necessary for de-
termining test frequency)
[DISPLAY] - VALUE
IMEASURE RATE] - SLOW
IMEASURE MODE] - TRIGGERED (neces-
sary for zeroing)
[EQUIVALENT CIRCUIT] - SERIES
EXTERNAL BIAS - OFF (slide switch)
4. Verify that the test frequency is 1 kHz (the
power-up default) by pressing [SHIFT]
[FREQUENCY].
The left-hand display should read 1.0000. If any
other reading is observed press [1][=][SHIFT]
[FREQUENCY]
5. Verify that the test voltage is 1 volt by press-
ing [SHIFT][VOLTAGE].
The left-hand display should read 1.0000. If any other
reading is observed, press [l][=][SHIFT][VOLTAGE].
6. Press the [FUNCTION] key to select
MEASURE function.
7. If the Digibridge has an interface option
(which has two 24-pin interface connectors
on the rear panel), be sure that the TALK
switch (rear panel) is set to TALK ONLY.
8. Zero the Digibridge as follows, before mak-
ing measurements.
Make sure that the MEASURE and TRIGGERED
keyboard indicators are lit.
A. Install the BNC cable and the Remote Test
Fixture (or whatever cable is appropriate)
as described in paragraph 3.2.
Note: make sure the test setup can accommodate all
components needed for performance verification. See
Table 5-1.
B. Press the [C/D] key.
C. Press: [1][6][9][3][=][SHIFT][OPEN].
D. Keep hands and all objects at least 10 cm
from fixture contacts.
E. Press START to initialize zeroing operation.
F. Wait until the GO indicator lights.
G. Press [1][6][9][3][=][SHIFT][SHORT].
H. Press START to initialize zeroing
operation.
I. Wait until the GO indicator lights again.
NOTE: For maximum accuracy, this zeroing procedure
should be performed at the start of each day and every
time the fixture configuration is changed.
9. Press the [MEASURE MODE] key to select
CONT. (continuous measurements).
10. Press [R/Q].
11. Insert, as DUT, the first resistor specified in
Table 5-2.
12. Verify that the displays are within the ex-
tremes shown for check number 1 in Table
5-2, if the resistor is within the tolerance
listed in Table 5-1.
NOTE ON TOLERANCES: Acceptable performance
of the instrument is bracketed by the set of display
“extremes” in Table 5-2. These are defined as the
nominal (ideal) measurements plus-or-minus the sum
of the instrument accuracy tolerances and the DDT
accuracy tolerance (or slightly more). If the accuracy
of your DDT is different from the recommendation,
revise the acceptable “extremes” accordingly. Notice
that this performance verification is NOT intended to
prove the accuracy of the instrument.
NOTE ON INSIGNIFICANT FIGURES: The right-
hand digit(s) of the display may be expected to flicker
and change (with the automatically repeating mea-
surements) if they are not significant for the specified
accuracy of the instrument. (See further comment
with step 21 below.)
13. Similarly, make the other checks indicated in
Table 5-2, under the R/Q parameter (checks
number 2, 3, 4, 5).
14. Press [C/D].
15. Insert as DUT the first capacitor specified in
Table 5-2 (check number 6).
16. Verify that the displays are within the ex-
tremes shown for check number 6 in Table
5-2, if the capacitor is within the tolerance
listed in Table 5-1.
17. Similarly, make the other checks indicated in
Table 5-2 under the C/D parameter (checks
number 6, 7, 8, 9).
In check number 8, verify that the fifth digit is reason-
ably stable, as follows. (Notice that the fourth digit is
the last significant one in the readout, for 0.02 percent
accuracy.) In check number 8, the flickering of the
fifth digit should stay typically between 2 counts.
For example, if the display is 330.1X µF, the “X”