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Harsh production environments pose real measurement challenges

Dayton, OH–February 2, 2016 Depending on the application, mill conditions can be harsh not only to humans but to the equipment used to control processing operations. Mechanical contact measurement systems face numerous challenges such as extreme heat, scale-build-up, and mechanical failure of parts.

For instance, consider slab caster operations. Slab casters typically run at slow speeds between 76 to 203 cm/min (30 to 80 in/min); billet and bloom casters typically run at speeds between 127 to 381 cm/min (50 to 150 in/min). The harsh environmental conditions along with the presence of slag or scale on the product’s surface make accurate measurements difficult to obtain using mechanical methods, such as with tachometers connected to a wheel or roller.

Tachometers operate by making contact with the slab or billet to measure the length and speed on continuous casters. These mechanical systems are subject to slippage and calibration changes caused by variations in the diameter of the roll or wheel due to dirt build-up or wear. The measurement error of mechanical systems will change will mill conditions, requiring the mill operator to continuously check the cut length accuracy through hand or weight measurements and then tweak the mill control system to keep cut lengths within specification.

The Beta LaserMike LaserSpeed gauge from NDC Technologies solves this problem because it uses advanced, laser-based technology to precisely measure the length and speed of hot steel and non-ferrous products without making contact. Because of the extreme heat conditions, the LaserSpeed gauge is housed in a stainless-steel, heat-protected environmental housing called the “X-Housing” and is mounted up to 2.5 meters away from the slab. This helps reduce cooling requirements and premature failure risk due to excessive heat. In addition, the LaserSpeed gauge eliminates the need for continual checks of cut length accuracy and constant tweaking of the control system. This results in money savings by producing the correct slab length required with minimal waste. Length and speed measurements are captured with better than ±0.05% accuracy, ±0.02% repeatability.