Expansion or Contraction control plays a vital role to be executed during the Heat-up or Cool down of a Glass furnace. Correct measurements and subsequent adjustments are key factors. Every care is taken to ensure liner displacements are measured. However small it may be on each individual crown segments other than the measurements recording the upward or downward movement of the melter, Working end and Regenerator crowns. Appropriate control is done by HTPL's highly experienced manpower.