DATREND Systems vPad-IV, Operating Manual

Page: 50 / 98

vPad-IV OPERATORS MANUAL
Windowed data analysis may be used when a manufacturer's inspection procedure or other test protocol
requires the device under test (DUT) to run for a period of time before testing is performed. This "pre-test
delay" allows the DUT to reach a stable operating condition before its output is tested. A disadvantage of
the protocol, however, is that diagnostic information about the DUT's behaviour during the startup phase is
lost.
vPad-IV is able to perform this test protocol without losing information by means of windowed data
analysis. Referring to
Figure 25
, start time
T
START
corresponds to the "delay" defined in the test protocol.
The "observation window" of
Figure 25
has a duration equal to the measuring time specified in the
protocol. The
Test Duration
of the Flow Rate Test is then made equal to the sum of the required startup
delay and the testing time or "observation time".
After the Flow Rate Test is completed, vPad-IV will determine the pass/fail result of the test based on the
volume and flow measured from
T
START
to the end of the test. Optionally, the Flow Rate Test may be
configured to include the "pre-test window" data in the Test Summary and assess these values to determine
the pass/fail result.
Windowed analysis per
Figure 25
is enabled by a checkbox which is shown when the Stop Test condition
is set to "when test duration is reached" ( Figure 26 ).
As previously described, the Test Duration is set equal to the sum of the startup delay and the testing
time specified in the original protocol, after which the checkbox can be selected. After enabling windowed
analysis, the analysis may be further configured by pressing the
Analysis Setup button. The windowed
analysis setup menu ( Figure 27 ) enables the start of the observation window, or T
START
of Figure 25 , to
be entered. Optionally, the test can be configured so that the reported results include the "pre-window"
flow and volume measured from time T = 0 up to
T
START
, and for the flow measured at T
START
to be
passed or failed based on the tolerance settings of the test.
Figure 26
Operation/Chapter 4
#
Page 34