Gas flow testers help the welder to Quickly an Easily Check Gas Flow at the MIG or TIG Torch Nozzle. This helps to diagnose Gas Flow Issues, Leaks & Restrictions. Browse our range of Gas flow testers for MIG Welding Torches and TIG welding Torches below. Our gas flow testers are suitable for CO2 and Argon gas. Gas flow testers are also known as Gas Flow Meters.