Standard Rotating Probes

High-resolution eddy current rotating probes for manual borehole inspection with the HRO hand rotating unit

High-precision differential rotating probes for reliable crack detection in boreholes. FOERSTER standard rotating probes are designed for high-resolution eddy current inspection of boreholes in combination with the HRO Hand Rotating Unit. Based on a differential probe design, they enable reliable detection of cracks and material discontinuities in safety-critical components.

The probes are suitable for borehole diameters ranging from 2.4 mm to 20 mm and ensure stable signal quality across a wide frequency range from 30 kHz to 3 MHz. A track width of 1 mm supports precise localization of defects during circumferential scanning.

Standard rotating probes are available in different mechanical designs. Depending on inspection requirements, probes with fixed diameters as well as split probe versions for inspecting multiple borehole sizes can be used.

With standard working lengths of 35 mm and 50 mm, the probes are optimized for typical industrial inspection tasks. Versions made of stainless steel or plastic are available depending on application conditions.

In addition to standard variants, FOERSTER also offers customized rotating probes tailored to specific inspection requirements such as probe system configuration, borehole diameter range, working length, frequency range, track width or probe material.

Product highlights

Your advantages at a glance

  • Differential probe design: Enables high sensitivity for reliable detection of cracks and surface discontinuities.
  • Wide borehole diameter coverage: Suitable for boreholes from 2.4 mm to 20 mm.
  • Flexible probe versions: Available as fixed-diameter probes or split probes for multiple borehole sizes.
  • Precise defect localization: Track width of 1 mm supports accurate circumferential inspection.
  • Optimized working lengths: Standard working lengths of 35 mm and 50 mm for typical inspection applications.
  • Wide frequency range: Usable from 30 kHz to 3 MHz for flexible adaptation to inspection requirements.
  • Application-specific materials: Available in stainless steel or plastic depending on inspection conditions.
  • Custom probe solutions available: Probe parameters can be adapted to customer-specific inspection tasks.

Technical information

Probe design Differential system
Borehole diameter range 2.4 – 20 mm
Working lengths 35 mm / 50 mm
Frequency range 30 kHz – 3 MHz
Track width 1 mm
Probe materials Stainless steel / plastic
Mechanical versions Fixed diameter / split probe design
Compatibility Optimized for use with FOERSTER HRO

Related products

HRO Hand Rotating Unit

High-resolution borehole inspection with rotating eddy current probes

Reference defect standards - Borehole

Reference defects for calibration of inspection systems using rotating probes