All-Metal Inductive Sensors for Identifying Fill Level of Molten Metals

Engineers have developed a sensor cooling system that encases the sensor in the same ceramic material as the tiles that insulate space shuttles against significantly excessive temperatures on re-entry to the earth’s atmosphere.   The routine industrial sensor chosen for the Sensor Cooling System (SCS) should display reliability in environments as much as 1200°C, be insensitive to collected dirt and mechanical stresses, and adapt simply to pre-existing installations and controllers.

Extreme range inductive sensors are suitable for this application. With all-metal, stainless steel housing (including sensing face) and IP68 and IP69K class protection they are suitable for harsh environments. With working distances as much as 40 mm and factor 1 for steel and aluminum, they fulfill application- particular requirements. In the first test phase, the water-cooled test piece was equipped with multiple temperature sensors and heated in a tube furnace to 1100°C. This test confirmed the computer simulations of the cooling system model. By optimizing sensors isolation, it was feasible to compensate temperatures as much as 1200°C. Additional cooling of air in the tube is carried out with an air exchanging instrument.