Measurement Principle

The unique touchless geometry sensor device consists of eight individual channels. Each channel measures at a frequency of 100 Hertz. The measurement frequency is approximately 100 cycles per second. In other words, each individual channel performs 100 measurements a second. The measurement principle is based on multi-channel eddy-current technology and performs touchless distance measurements from the sensor surface to the inner pipe wall. This allows for thorough geometry inspections.

The electromagnetic field created by the measurement system is independent of the type of medium in the pipeline – whether gas, water, oil, or air – as the differences in the magnetic permeability of these substances are negligible. The influence on electric permeability will be correlated with the Mechanical Dipper System and corrected by online recalibration techniques. This means that only ferric materials such as the pipe wall influence the electromagnetic field. Overlapping sensor measurement guarantees full circumferential coverage.

As the environment inside a pipeline is a perfect Faraday’s cage, there can be no interference for the electromagnetic measuring system even in the event of possible electro-magnetic influences from the outside.