Product Innovation Ltd invented this product in order to make marine diesel engines safer. These large engines can suffer from internal explosion due to an overheating bearing causing the oil to boil and subsequently explode. It was developed in conjunction with a small British Company and has been selling well for many years.

The essence of the invention is to use a different method of measuring the optical density of the oil mist in the engine. This novel method allows the resulting electronic instrument to react much more quickly to danger signals and to shut down an engine before permanent damage (or even explosion) occurs. The product now belongs to QMI Ltd, London.