sensors supplement Once a new product or technology idea has
been identified and accepted as a promising market oppor tunity, a feasibility study is implemented, either internally or with one of Alphasense’s academic par tners. It is normal for a number of such projects to be running simultaneously, because there is no guarantee of success, so Ar thur believes that it makes sense to ride more than one horse. Occasionally, new product ideas involve
the measurement of a new parameter, but more frequently, the requirement is an adaptation of an existing technology. For example, in the early years, most Alphasense sensors were employed for toxic gas detection in health and safety applications. Typically, these instruments would measure in the PPM range, but with increasing environmental awareness, customers began asking for sensors that could operate reliably in the low PPB range. This prompted a number of R&D projects that resulted in a range of air quality sensors that now sell in their 100’s of thousands all over the world. In addition to toxic gases, customers in the
environmental monitoring market also needed to monitor par ticulates. In most countries while toxic gases such as nitrogen dioxide are responsible for high numbers of premature deaths, the numbers attributable to fine par ticulates are even greater, so Alphasense developed a number of par ticle sensors that have become well established in the market. VOC monitoring is impor tant in both
environmental and safety monitoring, with volatile organic compounds representing both toxicity and explosion risks. Alphasense has therefore become one of the world’s leading
suppliers of PID sensors; typically selling around 30,000 per year. As well as new parameters and sensitivity,
the voice of the customer has also driven development work in areas such as power consumption and size. Both of these issues feature strongly in the objectives of most of Alphasense’s product developments. This is because instrument manufacturers are constantly looking for ways to improve the ease with which monitoring can be under taken, and this is significantly enhanced by making instruments that are small, lightweight and capable of running for extended periods without a requirement for frequent re-charging. Customers also look for sensors with a
wider range and reduced interference from other gases. This has resulted, for example, in over 20 different versions of the Alphasense CO sensor, with a variety of range options and significantly reduced interference from hydrogen. Occasionally, development work to reduce interference has also resulted in solutions that involve sensors working together.
TesTing and ValidaTion
For some reason, (presumably to lower costs) many sensor manufacturers batch test their products which means that they take a
selection of sensors from a production batch, test them and assume that the results reflect the status of the entire batch. Impor tantly, this has never been the philosophy at Alphasense. A bespoke test and validation facility has been constructed and developed over many years at the company’s factory near Stansted Airpor t in the UK, so that every single sensor is tested before it is passed for distribution. Typically, Alphasense manufactures sensors
in batches of 64. Often, all of the sensors pass the rigorous in-house tests, but occasionally maybe 62 or 63 will pass, so that is great news for customers because it means that they will not have to be person that finds the one or two in 64 that have failed the stringent testing regime. However, the major advantage of testing every single sensor is that this provides a fantastic oppor tunity to identify oppor tunities for improvement. By constantly testing every product, it becomes possible to figure out why some sensors fail to meet the required specification. A good example lies with the use of expensive noble metals. Naturally, manufacturers will want to minimise the amount of costly components, but at Alphasense, root cause analysis has occasionally identified the thickness of a sensor’s noble metal component as the source of potential failure, so the specification is changed to improve reliability. This may result in a slight increase in cost… but the cost of not doing so is greater! Many companies claim to operate a continuous improvement programme, but if you really want to be able to identify the root cause
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Instrumentation Monthly August 2021
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