Cooling plate thickness measurement in a blast furnace

A device for measuring the thickness of a cooling plate, said device being designed to fit inside a coolant channel of the cooling plate and comprising:

• a probe holder comprising a housing having a front sensor side and an opposite back side, an ultrasonic probe being arranged in said probe holder housing to be able to transmit and receive ultrasonic waves from said front sensor side;
• an expandable structure configured to deploy at the back side of said housing;
• and
• a flexible cord linked to said probe housing to assist the progression of said probe holder through the length of the coolant channel;
• wherein said expandable structure is configured to expand from a compact configuration to an expanded configuration, designed to bear against the inner surface of said coolant channel and bias the sensor side of the sensor housing against the inner surface of the coolant channel;
• wherein said expandable structure comprises a front and a rear lever articulated on the housing at opposite ends, and spring means arranged to bias said levers towards one another.