Shade range and sensor count are the two specifications that matter most in daily use. A wider variable shade range lets one helmet cover a broader spread of processes and amperages, tecproducts.co.uk from low-amp TIG work through to higher-output MIG or MMA, without swapping cartridges. More sensors generally mean the filter is less likely to miss a low-angle arc or a strike caught at an awkward viewing angle, which matters most for TIG welding where the arc can be harder for a sensor to pick up cleanly.
Plasma cutting uses a jet of ionised gas, usually compressed air, forced through a nozzle at high speed and heated by an electric arc to a temperature hot enough to melt through electrically conductive metal. The molten material is then blown clear by the same jet, leaving a narrow, clean cut. Unlike oxy-fuel cutting, plasma works on any conductive metal, including stainless steel and aluminium, not just carbon steel. Hypertherm is the plasma cutting brand we get asked about most, and it’s worth understanding the basics before comparing specific units.
Welding produces fume made up of fine particulates and gases, and the composition varies depending on the process, the filler material and any coatings on the base metal. Fume rises from the arc and, without adequate control, can build up in the breathing zone of anyone working nearby, which is why extraction is treated as a core part of workshop set-up rather than an optional extra.
Duty cycle is one of the most misunderstood figures on a welder’s spec sheet, yet it tells you more about real-world usability than the headline amperage does. It’s expressed as a percentage over a ten-minute period at a given output, so a machine rated at 30% duty cycle at its maximum amperage can run for three minutes out of every ten at that setting before it needs to rest and cool.
Switching speed, the time the filter takes to darken once it detects an arc, is worth checking against how you actually work rather than assuming faster is always better for every budget. For most general fabrication and repair work, a mid-range auto-darkening helmet with a sensible shade range covers the vast majority of jobs comfortably.
If you’re weighing up options for your own workshop, from portable units to fixed installations, it’s worth talking through the layout with a supplier who stocks a range of systems, such as welding fume extraction.
