For a continuous bioreactor perfusion process the PendoTECH Perfusion Controller has the ability to monitor and control the perfusion process separate from the bioreactor. The controller can monitor three PendoTECH Single Use Pressure Sensors that are integrated to alarms to monitor the performance of an external perfusion device such as a hollow fiber filter. These three pressures (Pin, Pret, and Pfil) are used to calculate delta-P and TMP which are required to measure filter performance. The Bioreactor Vessel weight control feature is used to replenish fresh media as spend media is removed by the filtrate pump in a constant flow set to a certain vessel volumes per day. The temperature can also be logged external to the vessel with a PendoTECH Single User Temperature Sensor. The filtrate scale can also be used to confirm amount of spent media removed. All data is logged to the file and can be trended to measure performance over a lengthy run.