The models 8500, 8505 and 9775 are designed to create welding shield gas. These gas mixers are suitable for:

• 0-50% CO₂ in Ar (model 8500)
• 0-10% O₂ in Ar (model 8505)
• 0-50% He in Ar (model 9775).
  
  Each gas mixer is easily changeable by adjusting a single calibrated dial.
  
  Since these gas mixers use Thermco's surge tank design, the gas mixture is highly accurate throughout the flow range.
  
  The digital, solid-state pressure switch controlling the surge tank pressure provides extremely long life as well as diagnostics for the surge tank pressure condition.