Pulse width - Pulse duration (width) allows you to adjust the depth of the penetration. When width is
increased it makes the penetration deeper and reduces the amount of heat entering the material
minimizing the risk of burning through thin sheets. Lower pulse width values should be used for higher
currents. Larger pulse width should be use for small currents, for example, a width greater than 50%
should be used for currents below 100A. Adjustment range: 10% - 90%
Base current –base current responds to the lower value of the current pulse. The base current is
responsible for maintaining the welding process. It makes it easier to control the amount of heat entering
the material. The base current adjustment is only possible during pulse welding. Adjustment range: 5%
- 90%
Downslope time –downslope refers to the gradual ramping down of welding current. Downslope allows
the welding current to be reduced gradually, allowing the metal to cool more slowly than it would without
downslope control
Crater current –crater current occurs after downslope time ends. It keeps the specified current to fill
the crater with a melted metal at the end of a weld. Adjustment range: 10A –200A
Gas pre flow –time from trigger activation until the arc is ignited. It should normally be longer than 0.5s
to provide enough shield gas to the nozzle. For a longer gas hose the gas pre flow should be longer.
Upslope time –current ramping time from start current to welding current. Adjustment range: 0s –10s
Pulse frequency –the frequency of how often the current value changes from base current to welding
current. Adjustment range: 40Hz –200Hz
AC frequency –a parameter that is most needed when welding aluminium. The greater the value the
better the weld quality and arc is more stable. Adjustment range: 40Hz –200Hz
AC balance –ratio between the duration of the positive to negative phase. Decrease the balance
causes more heat input into the material, resulting in a narrower joint and deeper penetration, a at the
same time reduces the thermal load of the tungsten electrode. Increasing the balance causes
introducing less heat into the material, resulting in better cleaning a broad joint and a shallow
penetration, however significantly increasing wear of the tungsten electrode. Adjustment range: 30% -
70%
Gas post flow –time taken form arc put out to completely cut of shield gas. Gas post flow time should
be long enough to prevent welding joint from oxidising and allowing the tungsten electrode to cool down.
Adjustment range: 0s –15s
3.Welding
3.1 Welding using MMA process
In MMA process arc is ignited by touching and rubbing the electrode against the material being welded.
Electrode tip should be cleaned from its coating to allow conductive inner core to contact with working
material.
3.1.1 Conducting the welding
Choose the welding process to MMA. In this mode you can only adjust welding current. You can adjust
the current value by turning the adjustment knob right or left.
