Braving the storm: calibrating load cells in marine environments
Load cells are used extensively in marine environments, from the legs of oil rigs to cranes loading container ships. Load cells are effectively self-contained, so can be manufactured to be totally waterproof and work reliably even when submerged for long periods.
One of the issues in marine environments is that a lot of equipment will be naturally in motion due to weather, tides and wave action. This is particularly true for mooring winches, which are used to tie a ship to its berth when in port. When a ship is loaded or unloaded, or in a high swell, the winching ropes can suddenly tighten or loosen. If the cables were held at a fixed length, they could easily snap or be damaged, even given their own natural elasticity.
Load cells in mooring winches continually measure the load on the rope, and automatically adjust the tension accordingly. Due to the constantly shifting environment, it’s important that winch load cells are calibrated on a regular bases. This can be done by switching off the winch and reducing the load to zero by slackening the rope, and then adjusting the load cell to zero as well. (Full instructions here if you’re interested! )
Calibration for all
Calibration of your load cells is important whatever type of environment they operate in. As we say in our own article:
“Calibration compares the accuracy of your load cell against a recognised set of standards. Load cells generally have accuracies of between 0.03% to 1%. Beyond this 1% figure, data becomes too inaccurate for most industries and applications. In addition, your business might need to demonstrate accurate results for product liability and safety issues, and traceability to a National Standard. You might also need this traceability is you wish to work towards ISO9000.”
All load cells are vulnerable to deterioration and inaccuracy; even a build up of dust can make the figures inaccurate. Load cells can also be affected by other faults including:
- electrical issues
- mechanical forces
- dirty and/or wet environments
- lack of regular maintenance
- faulty instrumentation
- loose cabling or connections
Recalibrate or replace?
Whilst recalibration can bring many load cells back into line with the required levels of accuracy, others may just have had too long or too hard a life. In these cases, it is far more cost-effective to simply replace the load cell with a brand new one rather then remove the old one, recalibrate offsite, put back in place, and then find it’s still not working properly.
Recalibrating load cells on an oil rig
It’s one of our favourite solutions to the issue of recalibrating load cells that sit under a massive structure. Read our article here to discover how to lift a North Sea oil platform off its legs, calibrate the load cells and pop it back nice and gently. The very neat solutions reduced the number of separate lifts required from 32 to 8 and eliminated the need to move equipment from one leg to another.
And there’s more…
Want to know more about load cells and polar bears, high heels, hairbrushes and more? We now have an impressive library of articles (blogs) on a vast array of topics, from the quirky to the essential. To search for a topic, simply type into the Search box (on the top menu bar) and hit the Search button. You can then qualify your search by ticking the Blogs tick box and clicking the grey Search button at the top of that page. All the results will be listed below. Here’s a search we prepared earlier on another of our favourite topics, load cells and stage performances.
Not found an article to answer your question?
Call us. Our team have years of experience in the design, manufacture and application of load cell solutions for a wide array of projects, from medical research to manufacturing, rom high performance racing cars to trampolines.
Christmas is coming
Just a gentle reminder that our manufacturing site will be closed for the holidays from Monday 23 December 2019 – Thursday 2 January 2020. Orders can still be placed through the shop during this period, however, they will not be processed until we re-open in the New Year. All load cell orders will be processed in the order they are received.
