Do you measure up?

Good measurement skills are essential to an efficient laboratory according to the National Physical Laboratory, Tom Ashby tells us why...

METROLOGY underpins many laboratory and manufacturing processes. It is key to ensuring satisfied customers and ultimately retaining and winning contracts. Yet metrology is often taken for granted, with engineers and researchers trusting automated machines to give them reliable answers. Many do so without understanding the process or the potential shortcomings of that approach. Setting out a measurement strategy is key.

Many laboratory products, valves for example, must maintain very tight tolerances to meet strict production requirements. When producing products such as inhalator valves, which will be relied upon to deliver the drug dosage, it is essential to produce parts without a single defect, as even minor inaccuracies can be costly.

Organisations realised that without a good grounding in measurement it would not be possible to produce the kind of consistency and accuracy needed for efficient production lines. Without the knowledge to question measurement and the ability to solve problems, poor decisions and costly mistakes were being made. Organisations were therefore missing out on opportunities to improve their productivity, efficiency and ultimately their bottom line.

In 2006, the National Physical Laboratory (NPL) recognised this industry requirement for better measurement training, so it launched the NPL Training Framework, initially developing a Level 1 course in Dimensional Measurement. Four years later, over 120 companies and 600 learners have gone through this framework with more signing up all the time - including major multi-national corporations such as Rolls-Royce, Lockheed Martin and Trescal.

A Level 2 course quickly followed, and in November 2009 NPL launched a set of large volume (LVM) metrology training units. These were launched in response to further calls from industry which had recognised the benefits of the existing framework. Further courses in these and other areas are in the pipeline, subject to feedback from industry, including electrical metrology, temperature metrology and calibration units.

Although the training shows organisations how to use the technology, it goes further into why measurement is important, how to approach it strategically and how to adopt responsibility for the process. The reason for its success is that it takes a generation of workers who have come to rely on measurement machines, and reintroduces the questioning and planning culture. This allows them to build systems and processes into their daily routine and so make more informed decisions and generate more reliable results.

Coordinate measurement machines are a wonderful thing but engineers need to

understand whether they are measuring a particular part or component using the most appropriate method. What are they actually measuring? Under what conditions? Should they trust the measurement result? People who have undertaken the NPL Training Framework start to ask questions like these, and they are finding there is often a better, more efficient way to measure.

NPL’s Dimensional Measurement Training Framework is made up of four levels, two of which are now available, with levels 3 and 4 in development. The courses, validated by The National Skills Academy for Manufacturing (NSA-M), are classroom based, supported by a workbook - with theoretical and practical exercises. There is an ongoing assessment process that provides the evidence that the learner has completed the course and the tasks within it.  Upon completion the learners receive an NPL certificate of qualification.

Level 1 is a three-day course that delivers the underpinning knowledge and expertise for anyone using dimensional measurement tools or requiring an appreciation of the importance of metrology. It covers an introduction to geometrical product specification, Cartesian and polar coordinate measurements, a guide to tolerancing and an introduction to the principals and methods of measurement. Fundamental measurement calculations are incorporated into the theoretical and practical exercises that are built in to Level 1.

Level 2 builds on what candidates have learned at Level 1, encompassing advanced geometric product specification, co-ordinate principles, first principle measurement, principles of process control, further measurement calculations and a competence unit in co-ordinate methods.

Companies quickly find that these “bite-sized” courses have a significant impact on the production process. One such company is Dawson Precision Components (DPC), a leading supplier of subcontract precision machining, which undertook level 1 training last year.

Its operators are from different backgrounds with different levels of understanding regarding technical drawings and use of measuring equipment. DPC invested in NPL Training to bring its employees up to a uniform level of ability. Employees gained a clearer understanding of geometric symbols and tolerances as well as increased confidence in inspecting various components.

The course showed employees that the standard way of measuring a particular feature is not always possible due to reasons such as feature size and accessibility, and how they could use alternative methods accurately and effectively. It provided a collective understanding of how to interpret drawings to avoid confusion, and an appreciation of the conditions or inaccuracies that can affect measurement as a whole.

Another good example is Darron-SBO, a leading precision engineering SME based in Rotherham, which provides specialist parts to the oil and gas industry, where tight tolerances and accuracy are essential.

Darron-SBO recognised that, with the expansion of its business and the increasing complexity of the products required by its customers, it was imperative for all quality related staff to have a high standard of competency in drawing interpretation and dimensional understanding. NPL helped it identify funding from Yorkshire Forward’s Enhancement Fund in order to put 21 members of staff through Level 1 and five through Level 2, at the end of 2009.

The firm is already seeing the benefits. Staff are thinking more carefully and making more informed decisions about which measurement method is appropriate for a particular task. As a result, the decision-making process with regards to quality and inspection has improved dramatically.

The training also enables the company to prove competency and unquestionable credibility to their customers, and managers at Darron-SBO are confident they will see a reduction in wastage as well as other business benefits.

Seeing the benefits the dimensional training was having, NPL met further calls from global businesses, including Airbus, Rolls-Royce and Boeing by launching a large volume metrology training programme. The courses - the first of their type in the world - will apply the training objectives of the existing framework to the equipment and methods used in large volume metrology.

LVM presents significantly different challenges due to the scale of the equipment and the environmental issues created by measuring outside the laboratory. But like the other courses, it is important that participants learn to question, understand and plan the best way to measure, beyond simply being able to use the equipment.

NPL recognises that industry looks to us, as the UK’s measurement institute, to offer support to ensure it benefits from the best possible measurement expertise. And that’s what we are trying to do with these courses. We see it as our role to offer industry and researchers access to the necessary training to improve the efficiency of their measurement processes.

In launching the large volume metrology units and continuing to develop other courses, NPL aims to help companies compete in a difficult economic climate, improve the manufacturing and engineering sectors’ skills, and underpin a key part of the future economy in the UK