The models 8510 and 8515 are capable of producing gas mixtures for a wide variety of applications. These mixers are adjusted at the factory to a specific mixture proportion; they may be adjusted in the field with the assistance of a gas analyzer. The model 8510 is used for mixing inert gases and the model 8515 is used for mixing when one gas is oxygen. The flow rate range is 0-750 SCFH.

These gas mixers are often used for specialty applications, such as leak detection mixtures, cover gas for molten metals, or unusual welding shield gas mixtures. 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. A pressure alarm system is optional.