The Pearl Project concerns a device, a system and a methodology that performs qualitative analysis of fuels or other clear liquids using spectroscopic analysis. The procedure carried out ensures that the fuel or liquid being tested is spectroscopically the same as expected and does not show color changes. The system is based on a special device designed to be placed in petrol stations to monitor the fuel leaving the fuel tank before it reaches the end consumer via the pump and it will have a sample container which will be renewed with new fuel every time there is liquid movement – that is, every time a customer supplies fuel. The device will apply a spectroscopic analysis periodically. The system concerns a network of (one or more) devices that will monitor fuel tanks in real time. The spectroscopic analysis measurements made by the devices will be sent to a central server where they will be analyzed.