Non-Destructive Testing (NDT) using ultrasonic technology

Ultrasonic pulse-echo measurement is a well-established Non-Destructive Testing (NDT) method for measuring wall thickness and detecting defects. When it comes to corrosion monitoring, ultrasound has distinct advantages compared to other available technoiques. It is noninvasive and measures the metal thickness directly and not via more or less dependable indicators.


Advances in low-noise electronics, sensor technology and signal processing algorithms now make it possible to achieve high resolution results using a permanently installed ultrasound unit.

Sensorlink utilizes ultrasonic pulse-echo technology to provide accurate measurements of internal corrosion and erosion rates.

Wall thickness

Ultrasonic measurement of wall thickness has conventionally been carried out manually by use of a suitable ultrasonic transducer and a measuring instrument. In most cases a basic probe utilizing a simple contact transducer to determine the thickness of the pipeline wall at a specific spot. This method usually yields a typical accuracy in the range of plus or minus 0.1 to 0.2 mm, depending on the skill of the operator.

The Sensorlink technology is capable of measuring changes in the wall thickness with greater accuracy, thus avoiding the uncertainty caused by inadequate instruments or unskilled operators. Wall thickness can be measured to a very high accuracy by repeating measurements at the same spot over time with permanently installed instrumentation.

Resolution of such high quality and accuracy has been made possible by careful refinement of Sensorlink equipment, production and technology, with notable innovations in the following areas:

  • Signal processing
  • Electronics with high signal to noise ratios
  • Optimum placement of transducers relative to the pipewall
  • Electronics and transducers capable of operating in seawater at great depth and in high temperature
  • Temperature compensation capability: the system is able to adjust to variations in the speed of sound caused by temperature variations in the medium (seawater or steel)
  • Delivers real time data
  • Automated measurement, logging and analysis
  • Flexible measurement intervals determined by client
  • Can be installed subsea
  • Can be installed on new pipelines or retrofitted to existing lines


The UltraMonit® system and the PipeMonit® system is used for monitoring the corrosion and erosion rates of pipelines. The system employs ultrasonic sensors to measure wall thickness, offering high resolution capabilities.

Sensorlink products are developed based on well-established ultrasonic and electromagnetic technologies. Our in-depth knowledge of the technologies and of our customers’ needs allows us to design products that meet the highest industry standards.

The advantages of Sensorlink products are:

  • Practical and easy to use systems developed according to customer needs
  • Top quality in line with the highest industry standards
  • Many communication methods and protocols
  • Online access to real-time information