MONITORING TO WORK FOR YOU
Example : Consider the need to produce an assembly consisting of two
pieces of 16-gauge steel. Published guidelines say that a welding current
of 15-12 kilo-amperes, a weld time of 10 to 14 cycles, and an electrode
force of 800 pounds will produce a good weld.
easily set the weld time, since almost all modern weld controls accurately
control cycles. You can calculate the airline pressure required to produce
the correct electrode force. Still, you need some kind of instrument
to measure weld current. For this, you need at least a simple weld monitor.
need to determine what combinations of current and cycles produce good
welds. By making a number of parts using various weld heats and cycles
and then performing nugget pull tests, you can determine the correct
heat setting for the chosen weld time without ever knowing current.
destructive testing takes time and may be difficult. In addition, parts
with several welds may exhibit current shunting from earlier welds.
Distance of the weld to the sheet edge can also have a major effect
on weld quality. These are examples where advanced weld monitoring techniques
- not just measurement - can help.
weld monitor is able to measure dynamic resistance, you can look for
formation of the weld nugget by observing how weld resistance decreases
toward the end of the weld. You may learn that some welds require more
current or that you can shorten weld time for others. Thus, monitoring
can help you better control your process and gain higher production
rates through increased knowledge of weld dynamics. Next