Page 29
The high voltage parameters for this custom instruction are identical to those set for the CH2 standard
high voltage settings. For more information on these tests and their parameters see Insulation
Resistance Test (IR Test) and Dielectric Withstand Test (DW Test) in the help system.
Note that Try It will not be active until after the HV Parameters window has been accessed at least one
time. Clicking on Try it will immediately perform the DW and IR tests and return the IR resistance if the
high voltage tests passes.
Bulk LV Isolation Test
Bulk LV Isolation Test with Search
The Bulk LV Isolation instruction allows you to perform a low voltage isolation test on a specified test
point with respect to a group of other test points (see Bulk Isolation Mode Below). The low voltage used
for the isolation test will not exceed the Compliance Voltage, which may be set between .25 and 10 volts.
The isolation resistance (Minimum IR Resistance) is specified. If the measured resistance is greater than
Minimum IR Resistance, the custom instruction will pass. If measured resistance is less than Minimum IR
Resistance, the test will fail. Using the dwell setting will cause the tester to apply the test current to the
test point, allowing the current to stabilize, before making the isolation measurement.
Note that the tester can perform LV isolation tests faster than it can HV isolation tests. Another
advantage is that the test voltage can be set low enough to ensure that any DUT circuitry is not damaged.
Setting a higher compliance voltage will allow the tester to see sense higher isolation resistances and
with greater resolution.
If you want the tester to locate the “failed to” test point, use the LV Bulk Isolation with Search custom
instruction. To test at higher isolation voltages above 10 volts see the custom instructions, HV Bulk
Isolation Test and HV Bulk Isolation Test with Search.
Bulk Isolation Mode
The Bulk Isolation Mode can be set as follows:
All
The isolation of the specified test point will be tested relative to all other test points in the test system.
Note that if All is selected, the test point must not be connected to any other test point (not be part of a
net), otherwise the custom instruction will fail. Therefore use of All should be limited to verifying that
individual “non connected” test points are truly isolated.
Lower
The isolation of the specified test point will be tested relative to all test points with lower system point
numbers in the CH2 test system. For example if this custom instruction were used for test point 147, test
point 147 would be tested relative to the test point 146, 145, 144, all the way down to test point 1. Note if
using Lower to check for the isolation of a net, it is important to specify the lowest system point of the net.
Otherwise this custom instruction will fail when other system points are found connected to the specified
test point.
Upper
The isolation of the specified test point will be tested relative to all test points with higher system point
numbers in the CH2 test system. If using Higher to check for the isolation of a net, it is important to
specify the highest system point of the net. Otherwise this custom instruction will fail when other system
points are found connected to the specified test point.
None
The isolation of the specified test point will be tested only relative to earth ground.
All but net
If other custom instructions connected the specified point with other points to form a net, the specified test
point is tested relative to all other system points outside the net. If the specified custom instruction is not
part of a net, the tester will test it relative to all other test points in the test system.
To Next Page
