8 – Master(tig) 2500, 2503, 3500, 3503 MLS™/ 0311 © COPYRIGHT KEMPPI OY(a)(b)3. OPERATIONWelding in places presenting an immediate fire or explosion hazard is forbidden!Welding fumes may cause injury, take care of sufficient ventilation during welding!3.1. WELDING PROCESSES3.1.1 MMA weldingMMA welding, as well as carbon arc gouging, is possible with all Master MLS and MastertigMLS power sources with all MLS panel versions when switched to MMA process.3.1.2 TIG weldingMastertig MLS power sources are designed especially for TIG welding. They are equipped withHF spark ignition and versatile panel functions depending on the panel used. The panels predo-minantly for TIG welding are MTL, MTX, MTZ and MTM. Also the MEL and MEX panel onMaster MLS power source can be used for TIG welding with contact ignition.3.1.3 Synergetic Pulsed TIG welding (a)MTX, MTZ and MTM panels include the synergetic pulsed TIG pro-cess, in which you only need to adjust the welding current while otherpulse parameters are programmed. Pulsing frequency is high, whichguarantees concentrated arc and increased welding speed.3.1.4 Long Pulsed TIG welding (b)This method gives you the possibility to adjust all pulse parameters.Weld pool control is also easier. Long pulsed TIG welding is includedin MTX, MTZ and MTM panels.3.2. OPERATION FUNCTIONS3.2.1. Power sourceAlways switch the machine on and off from main switch. Do not use the mains plugfor switching!Never watch the arc without a proper face shield designed for arc welding! Protectyourself and the surroundings against welding arc and hot spatters!3.2.2. Function panelsBefore welding starts, welding settings suitable for the work piece are chosen with the functionpanel. See 3.1. Welding processes.The Kemppi Multi Logic System, MLS, allows you to select from different function panelsaccording to your welding application. MEL and MEX panels are designed for MMA welding.MTL, MTX, MTZ and MTM panels are for TIG welding with basic functions, or with pulsedTIG, 4T-LOG, or MINILOG control of welding current, or with memory channels. See also 3.1.Welding processes.