Method for monitoring a fluid system lubricating a mechanical system

A method for monitoring a fluid system for lubricating a mechanical system, the fluid system comprising a tank containing a lubricating fluid inside a casing of the mechanical system, the fluid system comprising a spraying circuit provided with at least one sprinkler, the fluid system comprising a main fluid circuit extending from the tank to the spraying circuit, the fluid system comprising a back-up fluid circuit extending from the tank and joining the spraying circuit, the back-up fluid circuit comprising a back-up check valve configured to be either in a closed state preventing the lubricating fluid from flowing or in an open state allowing the lubricating fluid to flow from the tank to the spraying circuit, the back-up fluid circuit being dimensioned such that the back-up check valve is in the closed state in a nominal operating mode, the method comprising a monitoring phase comprising the following steps:

• detection of a malfunction by monitoring at least one monitoring parameter, the malfunction making the main fluid circuit inoperative;
• and
• detection that the back-up check valve is in the open state or the closed state;
• wherein the monitoring phase comprises the following steps:
• generation of a first alert in the presence of the detection of a malfunction and the detection that the back-up check valve is in the open state;
• and
• generation of a second alert different from the first alert in the presence of the detection of a malfunction and the detection that the back-up check valve is in the closed state.