Measurement of the wall thickness with CIRCOSON

Precision measurement of ferromagnetic steel tubes

The CIRCOSON WT sensor system works on the basis of the so-called EMAT (Electro Magnetic Acoustic Transducer) method. This method electromagnetically creates and receives ultrasound waves. The EMAT method facilitates ultra precision wall thickness measurements of ferromagnetic seamless steel tubes in accordance with international standards. The data is transferred directly to the CIRCOSON WT test and evaluation equipment where it is processed and analyzed. The system reaches a wall thickness measurement accuracy of approx. ± 50 μm and maximum throughput of up to 3.2 m/s during continuous testing.

The CIRCOSON WT system is often used together with the ROTOMAT and TRANSOMAT system. The latter perform additional material testing for longitudinal and transverse defects. As a complete system provider, FOERSTER develops tailored testing lines that perfectly meet your requirements.




Specifies the technical delivery conditions for steel tubes (housing, tubes, mechanical seals, and joint heads), coupling materials, and accessories. The requirements are also defined on three product specification levels (PSL-1, PSL-2, PSL-3).


Comprises specifications for seamless and welded steel tubes for pipelines in the crude oil and natural gas sector. The specifications of API 5L correspond to ISO 3183.

DIN EN 10893-12

Describes the automatic ultrasound wall thickness testing of seamless and welded steel tubes (except submerged arc welded tubes) across the entire tube circumference.