Since 1994, the US Center for Disease Control has required health-care facilities to house patients with infections potentially spread through the air in negative pressure rooms. Similarly, other organizations require positive pressure for surgical suites and areas with immune-compromised patients to limit the chances of infection spreading through the facility. TSI's PRESSURA™ Room Pressure Monitors accurately measure the actual room pressure differential, verifying the proper operation of your HVAC system to help you maintain patient safety.