Principle of operation
The closed recirculation loop is a proven method of directly monitoring hydrogen in liquid aluminum. A small volume of carrier gas, usually nitrogen, is brought in contact with the melt by means of an immersed probe that continuously circulates in the closed loop until its hydrogen content reaches equilibrium with the vapor pressure of H2 in the melt. The H2 concentration in the gas is measured and converted into a reading of the gas concentration in the metal. This method is fast, reproducible and accurate and can be used “on-line” on the cast shop floor.
The amount of H2 in the gas loop of the instrument is determined by a proprietary thermal conductivity sensor which provides high reproducibility and a broad measurement range. The analyzer has a built-in microprocessor which controls its operation and processes data.
The AlSCANTM system is built around a revolutionary, rugged and low-cost probe design.
The AlSCANTM probes are available in three different versions, adapting its use to a wide range of applications.
The three models are:
- HME0200D for wrought alloys
- HME0300D for foundry alloys
- HME1200D for long immersion and Strontium modified melts.
Longer probes of each model type are also available.