Identifying undesired conditions in the function of a floating roof of a tank

A control system for identifying an undesired condition in the function of a floating roof of a tank, said system comprising:

• an interface for receiving a filling level of a product in said tank, and a reference distance between a reference position on said roof and a surface of said product,
• processing circuitry for forming a reference distance deviation as a difference between said reference distance and an expected value, and comparing said reference distance deviation with a specified range,
• a memory for storing a data set comprising said reference distance deviation and said filling level if said reference distance deviation is found to be outside said specified range,
• said processing circuitry further being adapted analyze a plurality of stored data sets of reference distance deviations and filling levels, in order to identify said undesired condition.

A computer program product comprising computer program code to perform, when executed on a computer, the steps of:

• receiving a filling level of a product in a tank,
• receiving a reference distance between a reference position on said roof and a surface of said product,
• forming a reference distance deviation as a difference between said reference distance and an expected value,
• comparing said reference distance deviation with a specified range,
• storing a data set comprising said reference distance deviation and said filling level if said reference distance deviation is found to be outside said specified range, and
• analyzing a plurality of stored data sets of reference distance deviations and filling levels, in order to identify an undesired condition.