Thickness Measuring System

Exact material thicknesses in the calender process are the basis for a high-end product quality in tire production. The BST eltromat ProControl Indicon thickness measuring system makes it possible to determine the thickness of individual rubber plates on the top and bottom calender rollers and of the calendered material after the calender. High-precision, low-level radioactive isotopic sensors or laser sensors are used for measuring.

The values of the individual measuring positions are evaluated in a controller. In the data exchange with the calender controller, the positions and the axis positions of the calender rollers can be controlled over several closed control circuits. Comprehensive software tools are available for processing the measurement values in process data management syste


  • Versions with either two or three fixed sensors on the calender rollers
  • Version with one traversing sensor on the calender rollers
  • Single system, only for thickness measurement on the rollers or after the calender




  • Low-level radioactive isotopic sensors
  • (Strontium 90; 0.37 GBq, type X.117)
  • Laser triangulation sensors

The Measurements in Detail

  • Measurement of the top and bottom rubber plate directly on the calender rollers
  • Measurement of the total thickness or the basis weight
  • Determination of the steel cord height position within the overall composition
  • Measurement of the humidity of the textile cord in front of the calender

The Control Procedures in Detail

  • Different control algorithms can be implemented for a calender:
  • Gap control
  • Bending control
  • Cross axis control
  • Wire position control
  • Cascade control