Optical coil protection of 2 induction furnaces at Affilips N.V., Tienen, Belgium

LIOS DTS technology is being used for the OCP system to protect the integrity of the refractory lining of two 2.5-tonne vacuum-type coreless induction furnaces used for melting copper pre-alloys. These particular furnaces are operated in three-shifts to produce copper-iron pre-alloys. Such alloys pose exacting demands on the crucible material due to their aggressive chemical characteristics and fluidity. The tapping temperature is in the region of 1500 °C.


  • 1 OTS20P Controller, 2 channel fibre switch
  • Simultaneous monitoring of two 2.5 t furnaces (1200 kW, 200 Hz)
  • Connected to the JOKS-visualisation system via serial interface.
  • High precision measurement with 27 cm spatial resolution and less then 1 K temperature accuracy.
  • 2 x 60 m OCP sensor cable installed meander wise in two levels (top and bottom)
  • 2 x 20 m supply cable


April 2004


Over a span of a few charges, overtemperatures increasing from one charge to the next were identified in a specific position, and the system eventually generated alarms of the “deviation from average” type. The crucible was broken out, and a crack was found at this point which had allowed the melt to infiltrate the ramming compound.

Once a critical maximum temperature had been identified over several crucible campaigns, the OCP system was used as an indicator to identify the need for a scheduled re-lining.