A method for monitoring a filter installed in a fluid system. The steps include providing a reference region in the fluid system, the region including a chamber having a known volume and releasing a fluid from the chamber configured to flow through the reference region. The method further includes measuring pressure and temperature values at predetermined locations at predetermined time intervals and determining filter permeability values in response to measured pressure and temperature values. The method further includes comparing the filter permeability values to predetermined filter permeability values.