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Chelsea Technologies Limited


+44 (0)2084 819 000




55 Central Avenue
West Molesey
United Kingdom


Exhaust Cleaning, Low Sulphur Fuels, Turbidity, Greenship, Ferrybox, Environmental Monitoring, Salinity, Oil Spills, Fluorometers, Ballast Water Monitoring, Towed Oceanographic Platforms, Oceanographic Instrumentation, Hydrocarbon Detection, Oil Spill Monitoring, Algae Detection, ISO, Conductivity, Temperature, Depth, Plankton Sampler, Acoustics Transducers & Hydrophones, Sonar Evaluation Systems, Naval Oceanography Survey

Contact Name:

Justin Dunning

Contact Position:

Sales & Marketing Manager


Design, development and manufacture of oceanographic sensors and systems. Applications include environmental monitoring, sonar, military oceanographic systems, ballast water monitoring and exhaust gas scrubbing instrumentation.



Chelsea Technologies designs and manufactures ingenious environmental monitoring technology to make the world safer, cleaner and smarter.

Across shipping, marine science, water quality, defence and industrial process control, our best-in-class sensors and systems are trusted for the sensitivity, accuracy, reliability and sophistication. We’ve built our unrivalled specialist expertise over 50 years, and we apply this with new rigor to every engineering challenge our clients set us.

Our pioneering technology is helping to gauge shipping emissions, explore the oceans, create healthier fisheries, optimize crop spraying, improve production efficiency, even monitor microplastics and climate change.

This is the power of pure inspiration from Chelsea Technologies.



Sea Sentry – DNV GL Compliant Wash Water Monitor for Ship Exhaust Gas Cleaning Systems

Ship exhaust gas emissions from marine diesel engines release harmful gases and particulate matter into the atmosphere. Of particular concern are emissions comprising of NOX, SOx and hydrocarbon particulates, together with CO2, which are detrimental to human health and the environment.  To make ships greener and prevent pollution, the IMO has established a number of new regulations to reduce emissions.   One method of doing this is to clean emissions before release using an exhaust gas cleaning system. All varieties of wet scrubber systems use wash water which must be monitored at all times to avoid discharges that may exceed regulations & damage the environment.   CTG's Sea Sentry provides a wash water monitoring system - it monitors both the sensor inlet and outlet of wet exhaust gas scrubber systems. It is a turnkey solution which measures Polycyclic Aromatic Hydrocarbon, Turbidity (to ISO 7027: 1999), Temperature and pH. It incorporates an integral pump, de-bubbler, pressure relief valves and a flow meter.

FastBallast Portable Ballast Water Compliance Monitor

Chelsea Technologies Group’s FastBallast Portable Ballast Water Compliance Monitor is capable of determining the phytoplankton cell density of ballast water at the IMO D2 & USCG Discharge Standards (10 to 50 um range). The Compliance Monitor is available as a portable dual function discrete and flow-through analysis system, solely as a portable discrete sampling system or as a fully integrated system for continual flow-through analysis.   FastBallast is available in 3 separate solutions; a Discrete Sample Compliance Monitor, a Dual Function Compliance Monitor and as an Integrated Compliance Monitor. FastBallast’s cutting edge design enables such a rapid and detailed analysis that it is the only technology that can operate in flow-through mode, providing a continuous, real time update on discharge compliance. Therefore is can dramatically increase the volume of water analysed, producing a more representative sample.  FastBallast is fully automated, so all that is required is to pour a sample in to the chamber and press ‘run test’, FastBallast then displays results using a simple Pass/Fail outcome at the IMO D2 & USCG Discharge Standards (10 to 50 um range). It also displays a cell density number so that whoever is testing can see how close to the regulation boundary the sample is.

FastBallast Integrated Ballast Water Compliance Monitor

Chelsea Technologies Group’s FastBallast Integrated Ballast Water Compliance Monitor is an ultra-sensitive solution for continually monitoring large volumes of inlet and outlet water of a ballast water treatment system at the D2 (10 to 50 µm) regulatory limit. High sampling rates, made possible by incorporating a Single Turnover One Pulse (STOP) detection method, makes FastBallast better suited to analysing low densities of phytoplankton cells at the D2 threshold than more common (Multiple Turnover) PAM methods. FastBallast’s cutting edge design enables such a rapid and detailed analysis that it is the only technology that can operate in flow-through mode, providing a continuous, real time update on discharge compliance. Therefore is can dramatically increase the volume of water analysed, producing a more representative sample.

UniLux Fluorometer

Single parameter fluorometer which can detect one of Chlorophyll a, Phycocyanin, Phycoerythrin for algae monitoring and Rhodamine or fluorescein for dye tracing applications. It is also available as a nephelometer for turbidity monitoring.

TriLux Fluorometer

Multi-wavelength, digital fluorometer.  Applications include in-situ chlorophyll a & algae class studies, environmental monitoring, dye tracing, particulate studies, cell culture monitoring and process control.

UviLux Fluorometer

The UviLux is a family of sensitive, low cost, digital in-situ UV fluorometers designed for real-time monitoring of concentrations of refined & crude hydrocarbons, Coloured Dissolved Organic Matter (CDOM) and Tryptophan, a surrogate marker for Biological Oxygen Demand (BOD), optical brighteners and bacterial contamination in waste, recycled and natural water supplies.

TurbiLux Fluorometer

Sensitive, low cost digital IR turbidity sensor designed for compliancy with ISO 7027:1999 standard. TurbiLux can be deployed in a wide range of applications including flow-through systems for process monitoring and in-situ deployments in rivers, lakes and oceans.  

V-Lux MiniSonde

V-Lux is a miniature multi-parameter fluorometer configured to provide high quality in situ detection of either Algae, Aromatic Hydrocarbons or Tryptophan-like fluorescence. Fluorescence is automatically corrected for turbidity, absorbance and temperature to provide robust data collection over extended deployments.

Plankton Sampler

In situ zooplankton sampler, design for use in towed vehicles, on mooring and in ferrybox systems.

GlowTracka Bioluminescence Sensor

A submersible bioluminescence sensor which monitors the visible emissions from bioluminescent organisms in seawater. It is ideally suited to measure bioluminescence for toxic blooms and biomass studies to continental shelf depths.

Acoustic Transducers

CTG manufactures a range of underwater acoustic transducers including hydrophones, projectors, pingers and sidescan sonar arrays plus a wide range of state of the art equipment and systems for calibration, test & general performance evaluation of airborne, surface ship and submarine sonars.

Submarine Systems

CTG is the design authority for the Sonar 2115 military oceanographic system. Under a first-line supply contract Chelsea has supplied Sonar 2115 systems for installation onboard the fourth Astute Class submarine HMS AUDACIOUS and the Shore Based Integration Facility. Chelsea has previously delivered oceanographic systems for the first three Astute class submarines

Surface Ship Systems

Chelsea Technologies provides the UK Ministry of Defence with a customized FerryBox system for its Ice Patrol Vessel HMS PROTECTOR. The FerryBox system is designed to gather continuous real-time data of the surface waters through which the vessel travels. Also supplies towed vehicle systems for the RN Ocean Survey Vessels.

Pipeline Leak Detection System

The system finds leaks in sub-sea pipelines by sensing the fluorescence signal of leaking dye introduced during pipeline commissioning and operations.

Systems can also be provided to detect leaking hydrocarbons in operating pipelines, and for detecting leaks in control lines. The systems are designed to be easily fitted to an ROV for rapid deployment, and can also be supplied as a handheld system for diver operations

ERAS (Echo Repeat Acoustic Source) System

Echo Repeater Acoustics Source (ERAS) is a compact and versatile system for the performance evaluation of a wide range of active and passive sonar. It has been designed to be hand-deployed from small vessels with few facilities - the transducer assembly is a small lightweight unit containing both projector and hydrophone. At the surface, the system includes a rugged, portable, power amplifier unit and a controlling computer.

VASS (Versatile Acoustic Source System)

The Versatile Acoustic Source System (VASS) has been designed and developed by Chelsea Technologies Group to evaluate the performance of a wide range of active and passive sonar. It produces complex, calibrated transmissions in addition to echo repeating, transponding and acting as a calibrated receiver.

VASS provides a highly versatile and flexible sonar test system, which is configured by simple mouse or keyboard selections. In addition to instant configuration changes, via its Windows XP interface, VASS allows desktop set-up of complete trials programs in advance, hence avoiding costly errors in signal definition during calibration trials.

Oceanographic Towed Vehicle Systems

Chelsea Technologies Group is the world's leading designer & manufacturer of towed oceanographic platforms. We can offer small portable systems for use from small research vessels or ships of opportunity to large, dedicated systems that are permanently installed on ocean going research vessel.

FastOcean APD Profiling System for in situ estimation of Gross Primary Productivity (GPP)

Fast Repetition Rate (FRR) fluorometry provides a non-intrusive and non-destructive method for probing photosynthesis by phytoplankton. The two FRR fluorometers within the FastOcean Ambient Plus Dark(APD) profiling system generate the data required to estimate the electron flux through all photosystem II (PSII) reaction centres per unit volume of sea water, on wide spatial and temporal scales. Given that Gross Primary Productivity by phytoplankton (GPP) is generally the main sink for PSII electron flux, these data can be used to estimate GPP. When the APD system is not being used for profiling, one or both of the FastOcean sensors can quickly be removed from the frame and coupled with one or two Act2 laboratory systems (see separate brochure). The combination of FastOcean and Act2 allows fully automated fluorescence light curves (FLCs) to be run on discrete samples collected in the field or phytoplankton cultures.

Act2-based laboratory & FerryBox systems: Highly automated system for probing oxygenic photosynthesis by phytoplankton

Chelsea Technologies Group’s Act2-Based Laboratory and FerryBox Systems build on the highly successful FastAct system which has been widely used, in combination with the FastOcean Fast Repetition Rate fluorometer (FRRf), to run FLCs and other laboratory-based fluorescence measurements. The Act2 system marks a big step forward in terms of both performance and functionality. For example, the incremental steps available for incident photon irradiance (E) are much smaller and cover a much larger range (up to and above full sunlight). As with the FastAct, the standard Act2 FLC sample chamber provides full spectrum actinic illumination from filtered white LEDs. However, there is also an option to swap in 450 nm LED units. This allows for a spectral match to be made between the FastOcean FRRf and actinic illumination, thereby allowing for direct comparison of FRRf and FLC-derived data. Importantly, this feature also eliminates one of the spectral correction steps required in the estimation of primary productivity.

UV AquaTracka

A submersible fluorometer to monitor the concentration of refined hydrocarbons (360nm) or crude hydrocarbons (440nm) in a wide range of oceanographic applications. In support of this, it has been designed to be deployed from undulating vehicles, moored or profiling systems. The instrument is rated to 6000m.

AquaTracka III

A compact, lightweight, submersible fluorometer for the detection of chlorophyll a, dye tracing or turbidity. Manufactured in titanium, it is rated to 6000m. For deck and laboratory applications a flow through cowling is available.

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