Method for in-line control of the integrity of a filtering system

A method for in-line control of the integrity of a filtering system implemented in an industrial process involving the filtration of a gas through said filtering system, wherein the industrial process is an industrial process for which said filtration is a sterilizing filtration, said filtering system (F1;

• F2) comprising at least one filtering cartridge, the method comprising at least the following steps:
• a measuring step (S1) during which a pressure difference ΔP, representative of the pressure loss generated by the filtering system (F1;
• F2), is measured,
• a testing step (S2, S3) during which said measurement (S1) is compared to a predetermined upper threshold (Sh) and a predetermined lower threshold (Sb), in such a way as to consider said at least one filtering cartridge to be non-compliant when the pressure difference measured in the measuring step (S1) falls outside a range located between said upper threshold (Sh) and said lower threshold (Sb)
• said method comprising a preliminary step (S01) for measuring the pressure difference ΔP0 representative of the pressure loss generated by the filtering system when said at least one filtering cartridge is new, and a calibration step during which a calculation is notably used to determine said upper threshold (Sh) and the lower threshold (Sb) depending on said pressure difference ΔP0 measured,
• wherein the measurement of the pressure difference made during the measuring step (S1) is performed by means of a pressure difference measuring device having sensitivity of 5% or less of the value ΔP0 representative of the pressure loss generated by the filtering system when said at least one filtering cartridge is new,
• Wherein ΔP0 being the pressure loss generated by the filtering system when said at least one cartridge is new, and wherein the value of the lower threshold (Sb) is between 0.7*ΔP0 and 0.95*ΔP0 and wherein the value of the upper threshold (Sh) is between 1.3*ΔP0 and 3*ΔP0, and wherein the state of integrity of said at least cartridge in the sense that the filtered gas are considered sterile is implemented by monitoring only pressure difference ΔP, representative of the pressure loss generated by the filtering system (F1;
• F2).