Welding/Shielding gases are inert or semi-inert gases that are commonly used in several welding processes, most notably gas metal arc welding and gas tungsten arc welding.

Their purpose is to protect the weld area from atmospheric gases, such as Oxygen, Nitrogen, Carbon Dioxide, and Water Vapour. Depending on the materials being welded, these atmospheric gases can reduce the quality of the weld or make the welding process more difficult to use.

However, Semi-inert shielding gases, or active shield gases, include Carbon Dioxide, Oxygen, Nitrogen, and Hydrogen. Most of these gases, in large quantities, would damage the weld, but when used in small, controlled quantities, can improve weld characteristics.

Shielding Gases can be used as pure gases or as a blend of two or three of the following gases:

Helium (He)Carbon Dioxide (CO2)
Argon (Ar)
Oxygen (O2)Nitric Oxide (NO)Nitrogen (N2)
Sulfur Hexafluoride (SF6)Dichlorodifluoromethane (R12)
Hydrogen (H2)

Using the NovaCHROM 4000 GC, we can measure accurately your various mixtures of Welding/Shielding Gases.

Some common mixtures include:

75% Argon / 25% CO298% Argon / 2% CO275% Helium / 25% Argon
90% Argon / 10% CO275% CO2 / 25% Argon90% Helium / 7.5% Argon / 2.5% CO2
92% Argon / 8% CO275% Argon / 25% Helium90% Argon / 8% CO2 / 2% Oxygen

For handheld analysers please see the Veri-GAS range of analysers for measuring Carbon Dioxide and Oxygen.

Many other mixtures can also be analysed, so please contact us if you require any further assistance with your analytical needs.