ICON TECH BLOG #2: Dispersive Spectrometer

Icon’s technology blog, focusing on the industry-changing innovations integrated into our word-leading range of physical property analysers

Technology: Dispersive Spectrometer

Used In: Colour Opacity analyser

Dispersive Spectrometer – in Colour Opacity analyser

Instrumentation design is evolving. For many years, the predominant focus for analyser manufacturers was to produce an accurate measurement. This was often achieved regardless of maintenance requirements and overall cost-of-ownership; the most important requirement was that a measurement was made and the costs of supporting that were secondary considerations.

Times have changed. With advances in automation and remote communication, the focus has shifted to ensuring the measurement is more flexible and cost-effective. With fewer engineers now present on a plant or refinery, analysers must now more reliable than ever before; the maintenance requirements and performance diagnostics that prevent process failure and unwelcome downtime are crucial.

This changing outlook has directly influenced Icon’s redesign of physical property analysis, with our design ethos very different from the mindset that drove the development of existing technologies decades previously. Ours is a more holistic view that balances the demands of measurement accuracy, functionality, maintenance and overall cost-of-ownership – crucial factors that meet the expectations of today’s plant engineer. This has influenced the development of all our analysers, one being our unique Colour Opacity analyser.

The colour specification requirement for fuel product is obtained through the well-established principle: passing a single wavelength of light through the windows of a flow cell to obtain an output that correlates to a specific colour in the visible spectrum. However while the measurement is a relatively straightforward process, traditional colour analysers are prone to measurement failure caused by the gradual aggregation of dirt on the windows of the cell. This degrades the quality of the light signal; consequently the first time engineers often discover that flow cell windows are clogged are when the analyser stops working – and then need to contend with the cost and inconvenience caused by unscheduled downtime for emergency maintenance.

As Icon’s R&D team were approaching the redesign of a colour analyser with a wider outlook than simply outputting the required measurement, we wondered whether there was a simple but effective solution in the measurement technique that could mitigate this unwelcome issue?

There was. As the accumulation of dirt in cell windows is gradual, the clarity of the light source passing through deteriorates as the dirt accumulates. We realised that if the wavelength of the light source could be broadened to make a simultaneous measurement of this ‘opacity’ measurement - which is essentially a light transmission measurement - the analyser could monitor deterioration of the signal. This could enable users to predict cell failure and set a preventative maintenance agenda. A simple innovation in some respects, but a transformative one from a cost-of-ownership perspective.

By enabling our dispersive spectrometer to measure the full visible spectrum, the opacity measurement constantly monitors light transmission; when the signal is reduced to 10% of the transmission strength, an alarm is triggered. And by monitoring the deterioration of the signal, it becomes straightforward to anticipate failure: for instance if 10% of light transmission is lost every week, a preventative maintenance agenda can be set every 8 or 9 weeks to clean the windows. The process becomes more reliable, and planned maintenance means more uptime.

Find out more: http://www.iconscientific.com/products/colour-opacity