Corrosion-Erosion Monitor

The patented ClampOn non-intrusive Corrosion-Erosion Monitor (CEM) has been designed to monitor the average wall thickness of pipes, containers and any large object that requires corrosion/erosion monitoring. The ClampOn CEM system utilizes a unique method of monitoring wall thickness loss by the use of clamp-on sensors. A number of transducers measure corrosion-erosion by transmitting ultrasonic signals that propagate through pipe material. Using ClampOn acoustic transducers means that no drilling or welding that would cause loss of production is required.

How it works

The ClampOn Topside CEM is an non-intrusive ultrasonic instrument designed to measure wall thickness loss in pipes over a defined area. It uses active ultrasound and exploits the properties of Acoustic Guided Lamb Waves to detect the changes in wall thickness relative to reference values obtained during the installation of the system. Changes to wall thickness is detected by a grid of signal paths, generated by up to 32 transducers.


The permanently installed CEM system ensures that measurements are repeated frequently and in exactly the same manner, thereby eliminating the weaknesses of manual ultrasonic thickness gauging. Wall thickness trends are generated automatically and can be observed in real time.

Topside Corrosion Erosion Monitor


The Corrosion-Erosion Monitor consists of a Head Unit and up to 32 smaller transducers.

The Head Unit processes and controls the signals, communicating with the electromagnetic ultrasonic transducers which are fixed to the selected pipe section. The signal path follows the metal structure between the transceivers in operation, generating a matrix of measurements with thickness information. The number of Head Units and transducers to be used is decided by the client in consultation with ClampOn.

Accurate and reliable measurement of corrosion and erosion is a natural part of best practice, as this will enable you to monitor the condition of your pipes, determine inspection intervals more accurately, and ensure safer and more cost effective operation. Major operators have selected the ClampOn topside CEM as the best solutions for their topside assets and operations.

  • Real time
  • Non-intrusive
  • Retrofit installable
  • Large coverage area
  • Accurate/high resolution
  • Possibility for tomography


Our Corrosion Erosion Monitor will be interfaced using digital RS485 to a computer running our corrosion erosion software. The computer will then interface with the Control system using all available interfaces and protocols. It is optional how much data that will be sent across to the control system. As a minimum the average wall thickness will be used.


Corrosion-Erosion Monitor

Method of operation

Active ultrasound, guided Lamb waves

Transducer technology


Coverage area

Typical 0.3 m² to 1 m² [3.2 ft² to 10.8 ft²]


0.1 %

Wall thickness range

8 mm to 30 mm [0.3 in to 1.2 in] or 12 mm to 45 mm [0.5 in to 1.8 in]

Minimum pipe OD

114 mm [4 in]

Wall material

Conductive metals and alloys

Design life

25 years


32 channel main unit and PC/ automation controller


RS-485, Modbus RTU, Ethernet

System Supply voltage

18 VDC to 32 VDC or 100-260 VAC 50-60Hz

Ambient temperature head unit

-40 °C to 60 °C [-40 °F to 140 °F]

Ambient temperature transducer

-40 °C to 180 °C [-40 °F to 356 °F]

Cable interface

Cable with connector/Flying lead/Gland for cable access

Power Consumption

6.5 W operation, 4.5 W standby

Cabeling Minimum

4 x 0.75 mm² – Pending system configuration

Additional information

Contact us for more information.