IET Labs, Inc. RLC Digibridge 1693, User And Service Manual, Page: 92 / 171

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1693 RLC Digibridge
Operation
General Procedure.
1. Select units appropriate for the component
you plan to measure and a range that uses
the largest unit multiplier. (This is necessary
even if the measured value of the DUT is very
small.) Select ENTER function.
2. Enter the nominal ratio (see above) as the
bin-limit “nominal value”. Ignore units and
multiplier (although those selected in step a
will still be displayed); the number entered
will be used by the Digibridge as a ratio
reference.
3. Enter (as usual) the desired set of tolerances
for bin sorting. (If sequential limits are de-
sired, also enter another nominal ratio, limits
for other bins, etc.)
4. If you plan to measure large-value compo-
nents, make no change in range. (However,
if you plan to measure small-valued com-
ponents select a range that uses a small unit
multiplier.)
5. Enter the nominal value to be used by the
Digibridge in the ratio calculations. Notice
that units and multiplier are displayed. You
can calculate what to enter as follows:
(expected typical measurement)/(corresponding ratio to
be displayed) = nominal value to be entered
6. Enable ratio measurement
(measured value /nominal) as usual.
NOTE: if you want the other ratio (nominal / measured
value) instead, then the calculation in step 5 has to be
the product (expected measurement)*(corresponding
ratio).
7. Select MEASURE function and proceed with
measurements. Display selections VALUE,
delta%, and deltaRLC will all display the
ratio; BIN NO. will display the bin assign-
ment. With a few strokes of the (DISPLAY]
key, it is easy to obtain both ratio and bin
number for each DUT (even without using
the IEEE-488 interface).
Example 1
. To sort 200-mF capacitors in bins of ±5%.
10%, and 20%. Displays to be ratios that can be inter-
preted as Cp values in mF and dissipation factor D.
1. Select units appropriate for the component:
A. Select PARALLEL equivalent circuit and
ENTER function.
B. Press [C/D]
C. Hold range 4 by pressing [4][=][SHIFT]
[SPECIAL][I]
2. Set up nominal ratio to look like 200 mF by
pressing [2][0][0][=][SHIFT][NOM VAL]
3. Set up symmetrical bins as stated above:
A. [5][%][=][SHIFT][BIN NO][0][1]
B. [1][0][%][=][SHIFT][BIN NO][0][2]
C. [2][0][%][=][SHIFT][BIN NO][0][3]
4. No action is required; range is correct.
5. Enter the nominal value:
A. Calculate: (200 000 µF) / (200) = 1000
B. Press [1][0][0][0][=][SHIFT][NOM VAL]
6. Enable the ratio mode (measurement/nomi-
nal) by pressing [2][=][SHIFT][SPECIAL]
[6].
7. Select MEASURE function and make mea-
surements as usual.
If you enable VALUE display, the ratio shown can
be interpreted as value in mF, and the measured D is
also displayed. If you enable BIN NO. display, the bin
number only will be shown.
Example 2 . To sort l mΩ resistors in bins of ±1%, 5%,
and 10%. Displays to be ratios that can be interpreted
as Rs values in mΩ (with better resolution than dis-
plays in ohms) and Q. NOTE: If the display resolution
were not important, normal binning procedures would
be sufficient; ratio measurement is not necessary for
this binning.
1. Select units appropriate for the component:
A. Select SERIES equivalent circuit and
ENTER function.
B. Press [R/Q].
C. Hold range 1 by pressing [l][=][SHIFT]
[SPECIAL][1].
2. Set up nominal ratio to look like 1 mΩ by
pressing [l][=][SHIFT][NOM VAL].
3. Set up symmetrical bins as stated above:
A. [1][%)[=][SHIFT][BIN NO][0][l]
B. [5][%][=][SHIFT][BIN NO][0][2]
C. [l][0][%][=][SHIFT](BIN NO][0][3]