Dr. Livingstone, I Presume WELDWISE 2400 - Manual (Page 28)

0430-INS-400 Rev. D
3-4
To resolve this issue, the exact time (in halfcycles) needed for the weld current to burn through the
coating could be determined by examining collected weld data. Using this information, a segment
could then be added that would effectively divide the Weld segment into two. The first Weld segment
would start when the weld current fires, and would end when the coating had been burned off. The
weld current tolerances in this particular segment could be widened to accommodate the change in
current density when burning through the coating. The second Weld segment would begin at that point
when the weld current had reached the metal to be welded, and would end when the weld current
ceases. In this segment, the weld current tolerances could be tightened to ensure the necessary amount
of current (in the example, 12 KA, +/- 0.5 amps) to make a good weld.
Segments provide a useful means for organizing the weld data and comparing changes over time. The
ability to specify different tolerances within several different segments allows the user to precisely
isolate weld factors that may be critically important to weld integrity and include these factors when
accepting or rejecting welds.
Data Collection
Data can be collected for each halfcycle, segment and/or weld. Please refer to the General Setup
Menu in section 6, WMS Reference Guide.
Weld data is continuously recorded whenever the weld monitor is operating, however only a pre-
specified amount of data is stored. The monitor is 'triggered' at the instant that weld current is fired;
this moment is referred to as the trigger. The quantity of data stored is based on the trigger. The user
can choose a number of halfcycles prior to the trigger (the Pre-weld segment) and a number of
halfcycles after the current has ceased (the Post-weld segment), depending on the importance of this
data to weld analysis.
For example, a weld schedule may have 8 cycles (16 halfcycles) of Squeeze, 12 cycles (24 halfcycles)
of Weld and 8 cycles (16 halfcycles) of Hold. In this particular process, the force during the last six
halfcycles of the Squeeze period and the first eight halfcycles of the Hold are especially important.
Accordingly, the segment length can be set to include only those specific halfcycles. All additional
data before and after the indicated number of halfcycles would consequently be discarded by the
monitor.