A 20t capacity load cell, manufactured by Straightpoint (SP) in 1994, has been returned to Holyhead Marine Services, of North Wales, UK having completed its latest inspection and calibration. The Load Link is the latest in a series of historical force measurement devices to pass through SP’s in-house testing facility recently.
In order to maintain the accuracy and function of a lifting load / force measurement product, be it SP-branded or otherwise, scheduled calibration and maintenance needs to be carried out to ensure continued safety when applied in the field.
SP can apply and exert a wide spectrum of known loads and forces, from just a few kilograms or pounds to many hundreds of tonnes, in order to test and calibrate load cells and force sensors supplied by clients. Machines installed at SP headquarters in Hampshire, UK are UKAS ISO 17025 / NIST traceable rigs, Class 0.5 standard, and certified by the National Physical Laboratory in London.
Josh Young, calibration technician at SP, who completed the latest inspection on Holyhead’s Load Link, outlined the process: “We always carry out a visual and functional check of the load cell prior to putting it in the test machine. This includes checking that the gaskets are sealing the unit sufficiently and that the load cell powers on and responds to loading by hand. For every re-calibration we do a set of ‘as found’ readings which are taken before any adjustment. It’s from here we can see if the load cell meets tolerance and then adjust it accordingly.”
He continued: “We exercise the product to its working load limit and back to zero. Then we take our as found readings; if it passes we take the load cell out of the machine and re-zero. However if it doesn’t pass as found then we must adjust it and take a set of definitive readings.”
Young explained that it is common to receive a load cell that has been working in the field for many years. “In total, a third of the load cells we get for recalibration could be deemed to be ‘old’,” he said. “It’s one of the most interesting facets of working in the team; it demonstrates the quality of the products we manufacture but these historical units serve as time capsules from which we can measure the technological advancements we’ve made—and continue to make.”
David Ayling, director at SP, said: “We spend a lot of time and money on enhancing our product range, and working with our industry partners to expand our offering and challenge the performance of our existing load cells. However, we rarely take an opportunity to celebrate the longevity of our more traditional products that continue to perform accurately and reliably in the field. The aforementioned Load Link from the marine sector is a prime example.”