The sensor
is installed in the roof of the protection structure of the christmas tree or the production manifold. The roof functions as a collector and for this reason it needs to be tight. Because hydrocarbons (Oil and Gas) are lighter than seawater, it will float upwards and be caught in the collector. A layer of the leaking media is built up and will eventually cover the sensor window. The sensor will measure another media than water and transmit a changed signal through the Subsea Control Module to the operator topside.