The invention is a method and a device for measuring the filtering or purifying
capacity of a purifier. The invention allows the use of a single analyzer for sampling
the inlet and outlet streams. This is accomplished by sampling the inlet stream
only at some times when the change in the inlet stream is expected to occur. At
other times the outlet stream is sampled to monitor its composition. A computer
system on the basis of the accumulated data decides when it is time to replace
or to regenerate the purifier or the filter bed. The computer system also determines
the strategy of when to sample the inlet stream. Various system sensors may be
used to make this determination, such as pressure sensors and level sensors. The
data from other sensors, such as flow sensors, may be used in the calculations
performed by the computer system.
