A pressure swing adsorption system including a plurality of vessels having one or more layers of adsorbent material therein, a feed gas channel, a waste channel, and a product channel. The system also includes at least one parallel channel connected to each of the vessels via a respective conduit with a valve. At least one pressure measuring device i configured to measure a pressure within the parallel channel. And, a controller is provided that is configured to monitor the at least one pressure measured by the at least one pressure measuring device during a PSA cycle performed within the PSA system, in order to determine the performance of the cycle and monitor proper operation of the system.