System and method for measuring cooling plate thickness in a blast furnace

A system for measuring a thickness of a cooling plate, said system comprising:

• a probe holder unit designed to fit inside a coolant channel of the cooling plate, the probe holder unit comprising a housing extending along a length axis from a first end to a second end, a lateral, sensor side and an opposite rear side, an ultrasonic probe being arranged in said housing to be able to transmit and receive ultrasonic waves from said sensor side;
• a rear housing part being moveably arranged at the rear side, transversally to the length axis, and elastically biased away from the sensor side, thereby permitting the probe holder unit to adapt to the cooling channel size;
• a drive chain to assist the progression of said probe holder unit through the length of the coolant channel, said drive chain linked to first connecting means at said first end of said housing;
• a cable assembly comprising electric wires connecting the ultrasound probe;
• an encoder arrangement configured to cooperate with the drive chain to measure a length of drive chain passing along it, the encoder arrangement comprising a first gear meshing with said drive chain and coupled to an encoder.