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F256-Z3699 - Measurement Of Small Forces In Deep Water

An exchange of resources between the British loadcell manufacturer Novatech Measurements Limited and the USA's National Oceanic and Atmospheric Administration has enabled the development of a 1kgf rated low range loadcell for underwater use. The loadcell can function in the high pressure environment found on the ocean floor at a depth of 6km while performing measurements to within 1% of its rated load of just 1kgf.

This is a major step forward for loadcell technology operating under high fluid pressures, where existing high pressure casings for force sensors were only suitable for high force measurements above 20 tonnef or 200kN. Novatech's design enables lower rated loadcells down to just 100g or 1N rated load to operate in high pressure underwater environments.

Novatech offered a sale or return prototype of their low force loadcell to NOAA who used their state of the art environmental test facility to explore the capabilities of the new loadcell. The prototype design was successful with just the raw data, without correction curves, showing that the loadcell could repeatedly measure a 440 gramme test weight between atmospheric pressure and 600 bar to within 9 grammes (or approximately 0.1N).

NOAA's Application

NOAA is monitoring a suite of oceanographic processes, including ocean currents and temperature, using ocean bed sensor arrays sited 6km below the ocean surface, which are coupled to surface buoys via high performance mooring lines. The buoys relay data to space based satellites which otherwise would be unable to communicate with the sensor arrays through the deep oceans.

Over the 6km depth, the mooring lines are subjected to self weight, fluid flow and buoyancy forces. The high pressure environment effects the mooring line buoyancy through fluid density changes and volumetric changes in the mooring lines jacket material.

Using the new Novatech low force loadcell NOAA are now able to measure the change in buoyancy forces as a function of water depth within a recreation of the oceanic pressure environment in their high pressure test chambers.

You can see more about ocean monitoring on the NOAA website. Follow the links in the Explore NOAA section.

We are happy to design variants of this loadcell to meet your requirements. Please consult our engineering department.