Subsea Particle Monitor

The ClampOn Subsea Particle Monitor is a non-intrusive sensor that detects and monitors sand in the production line.

Sand production in Oil and Gas wells is one of the most challenging factors an operator faces during production. Going subsea, safety issues in conjunction with the need to produce as much as possible  per well, makes the selection of a subsea monitoring system even more important.

How it works

The ClampOn subsea sensors are designed to meet these requirements:
  • Designed for a service life of more than 25 years
  • Independent redundant electronics
  • Independent high and atmosphere pressure chambers
  • Electron beam (EB) welding of the chamber against external pressure (no rubber or mechanical seals)
  • Glass-metal penetrator as a barrier between high and atmosphere pressure chambers
  • Outstanding sensitivity, repeatability, accuracy and signal/noise ratio thanks to Digital Signal Processing (DSP)

Principle of operation

The ClampOn DSP Subsea Particle Monitor is based on the ClampOn “Ultrasonic Intelligent Sensor” technology. The sensor is installed two pipe diameters after a bend, where the particles/solids impact the inside of the pipe wall, generating an ultrasonic pulse.


The ultrasonic signal is transmitted through the pipe wall and picked up by the acoustic subsea sensor. In the patented “Intelligent” ClampOn sensor the signal is processed internally by a DSP engine and filtered before being sent digitally and/or analogically to the topside computer or control system (no Calculating Interface Unit required). Here the user can monitor and evaluate the data in real time and make the required decisions for profitable production.


Figure shows what sand management is about. The closer to the red line the operator can produce safely the more profitable the wells become.

Sand production in oil and gas wells is a serious issue for oil and gas producers. The challenge is not merely to avoid sand production, but also to increase commercial well productivity, as even small quantities of particles in the well flow can cause significant damage. As an operator you are interested in maximum production and profit from your wells, no matter what technology you use. Operators all over the world have made ClampOn their preferred supplier of sand monitoring systems, due to the patented technology that turns their wells into profit generators.

The ClampOn DSP Subsea Particle Monitor incorporates a new filtering technique that makes the sand detector an extremely useful tool for analyzing the true nature of sand production, helping to control it and finally, increasing the profit from the well! This filtering technique is the result of integrating our experience of thousands of wells, analyzing data, and using the results to enhance the technology used in our ClampOn DSP Subsea Particle Monitor.

The enormous capacity of the DSP sensor (the only one on the market) makes it possible to scan through a frequency range of 1 MHz 128 times per second. This illustrates the capacity of our technology and of the filtering technique that is at the core of acquiring and processing sand data.

The signal from the sensor experienced on a high flow rate – high pressure gas well using a traditional/alternative sensor without DSP-06 filtering technology.

Sensor signal experienced on the same well, now with the new ClampOn DSP filter. This shows how the sensor has completely removed the flow noise, allowing the operator to monitor the true nature of the sand being produced.


All our instruments are equipped with digital interface, and comply with all common protocols. Our instruments can easily be integrated into any existing or new control system. A computer with our software is often used in-between our instruments and the control system. The computer will be used for sand calculation by using the RAW data from our sand detectors and flow data from third party systems, then output calculated sand rate to the control system. All recorded data will also be stored for analyzing and calibration purposes. We always recommend using the digital interface due to following benefits:

  • Two way communication enabling instrument software update and configuration
  • Full signal range resolution
  • All sensor data can be transmitted
  • No signal loss


Subsea Particle Monitor

Method of operation

Passive acoustics (ultrasonic)


Intelligent DSP electronics inside sensor unit

Method of installation

Non-intrusive, clamped to pipe surface

Minimum particle size*

Oil/water: 25 microns/1PPM
Air/gas: 15 microns/1PPM

Minimum sand rate*

0.01 g/s

Minimum flow velocity*

0.5 m/s


Better than 1%

Interface options

RS485, Modbus, Canbus, SIIS

Two-way communication


Software upgradeable


Flow regimes

Oil, gas, water, multiphase

Optional features

Onboard Sand Calculation
Self Diagnostics
Vibration monitoring
Temperature measurement

Max water depth

3048 meters [10000 ft.]

Design lifetime (MTBF)

220 000 hours (25 years)

Hose/jumper interface

Bennex or ODI / jumper or bulkhead


ø90 x 324mm [ø3,5” x 12,8”] / 7kg air (5kg water)

Power supply

12-28VDC, 1.2W (single electronics)

* Depending on flow conditions

All specifications are subject to change without notice.