Contamination control is of utmost importance in clean room. High air change rates and laminar air flow are two of the methods used to keep impurities away from critical product. Yet, these measures can become ineffective if the clean room pressure differential should go negative, in effect sucking contaminants in. PresSura clean room pressure controllers constantly measure the room pressure differential and adjust the exhaust volume to correct problems as they occur. Should the room pressure differential rise too high or fall too low, the PresSura controller will signal an alarm so appropriate action can be taken.