HUNTER – Advanced Magnetic Adhesion Inspection Crawler

Hunter is a modular remote access crawler designed for cost-effective NDT ultrasonic imaging of ferromagnetic structures such as storage tanks, pressure vessels, large diameter pipes and ship hulls without the need for rope access; thus, eliminating potential risks associated with manual inspections specifically in hazardous or difficult to access terrains.

NDT Inspection Tasks:

Corrosion mapping.

Thickness gauging/B-Scan.

Weld inspection and critical defect sizing.

Visual inspection.

Hunter Packages

The Time of Flight Diffraction (ToFD) weld inspection package provides accurate ultrasonic inspection technology, principally intended for detecting welding defects.

  • Full volumetric coverage for defect detection in welds.
  • Able to measure ‘through-wall’ extent of defects.
  • Uses its water irrigated TOFD probes provides for rapid weld inspection.
  • Provides Fast, proven and cost-effective inspection.
  • Allows for data analysis and reporting from visual representation of the inspection data

The Phased Array weld inspection package uses multi-element transducers and multi-channel instrumentation, which electronically steer and/or focus ultrasound.

  • Assesses the volumetric extent of the defects in welds.
  • Using the water irrigated phased array ultrasonic probe provides for rapid and full volumetric inspection.
  • Use of multi groups provides code compliant inspections.
  • Allows for defect characterisation, interpretation and reporting from the Visual representation of the inspection data.

The Ultrasonic B-Scan package provides cross sectional a detailed end view of the object under inspection along a single axis. This provides more information than would a manual thickness survey based on statistically selected data points.

  • Thickness measurement readings every 1mm / as specified by the user.
  • TR probe (Dual crystal) for good near surface resolution.
  • Data visualization – Plot of thickness readings across different courses of storage tank wall, along one line.
  • Improved Inspection capability due to its the data visualisation capability

The Ultrasonic Corrosion Mapping package is an ultrasonic technique which creates surface map of the area inspected and identifies variations in material thickness due to corrosion.

  • Measures the extent of corrosion.
  • Use of water irrigated TR probe (Dual Crystal) provides optimum UT performance.
  • Provides 2-D plot of the corroded area.
  • Optional coarse scan for high speed screening.
  • Visual images of the inspected area (corrosion map) available for reporting.

The Phased Array Ultrasonic Rapid corrosion mapping package provides quick.

  • Measures the extent of corrosion.
  • Use of water irrigated phased array ultrasonic probe provides rapid performance.
  • Provides a 2-D plot of the corroded area.
  • Provides 12 times more coverage than with standard UTprobes.
  • Position localisation for repeat scans.
  • Visual images of the inspected area (corrosion map) available.

Key Benefits


Ease of use and deployment.

Hunters intuitive user interface allows it to be deployed and controlled by a single operator with ease. It only takes a few minutes to attach/detach the inspection packages (TOFD, B-SCAN and Corrosion mapping).

Provides Credible data.

Hunter significantly improves the quality of data collected as it moves over inspection surfaces, providing auditable results with the elimination of human error. Hunter’s ability to continuously record NDT signals also ensures instant reporting of signals in real time for data analysis by the operator.

Allows for frequent cost-effective inspection.

Hunter’s unique advantage is its ability to conduct both statutory inspection and Risk Based Inspection (RBI) guaranteeing cost savings for the asset owners. A low overall cost of inspection provides for cost effective asset management.

Typical Applications

Key Features



Multi NDT Capabilities.

Modular design.

Technical specifications

Technical Specification of the crawler only

Dimensions:410mm x 470mm x 200mm (L x W x H).
Adhesion:Neodymium Magnetic wheels.
Drive:Precision drive.
Wheels:High Wear resistant non-slip rubber coating.
Speed:150mm/s max.
Umbilical cable:30m.
Pumping system:30m height.
Power supply:110 AC-230AC, < 500W.

Technical specification of NDT system Application

Probes:Dual/single crystal probes from 1 to 10MHz.
Transmitting pulses Voltage:Up to 200 Volts.
Digitizer:8bits at 100 MSPS.
Filters:10/5/2.5 MHz broadband.
High Pass Filters (-3bd):0.25, 0.5, 0.75, 1.0,2.5, 5, 10MHz
Low Pass Filters (-3bd):1, 2.5, 5.0, 7.5, 10, 15, 20, 30 MHz
Programmable gain:0 to 100dB’s.
Visualisation:A-scan, B-scan, C-scan.
Application (Typical):TOFD, B-SCAN, Corrosion Mapping.