Low cost optic sensor for hydrocarbon detection in open oceans

Hydrocarbons are one of the most important toxics in the oceans. Their presence may cause the death of organisms. They even can affect to the human beings, when they consume products that have been in contact with the hydrocarbons. After a hydrocarbon spillage, the fishing activity, the tourism, the safety and the wildlife are endangered. The fast detection is very important in order to start as soon as possible the cleaning tasks. It can be done using sensor networks. The first step in order to create a water quality monitoring system is to obtain a good hydrocarbon sensor. The sensor must be robust and cheap. There is no needed of high accuracy, the objective is just to detect the presence of the hydrocarbon in the water surface. In this paper, we present a low cost optic sensor capable of distinguishing the presence or absence of hydrocarbon in the water surface. The sensor is formed by light-emitting diode (LED) as a light source and photoreceptor as a receiver. In order to create the sensor, several tests have been done using different light sources. The light sources have different wavelength (violet, blue, green, orange, red and white). In order to test our samples, six samples are prepared. The samples are made of sea water and fuel (as they are one of the typical hydrocarbons). After the first tests, the best wavelength is selected and it is studied in detail. The lights selected were violet, orange and white. After the detailed tests, the light source that offers best results was the white light