Article | April 16, 2009

Article: Logically Controlling Airflow: Advantages Of The Logic ECM

Source: Labconco Corporation

The Purifier® Logic™ Biosafety Cabinet has a patent pending process for controlling airflow. At the center of this process is its Electronically Commutated Motor (ECM), which precisely monitors and controls airflow through the cabinet without the need for sensors. While there are other manufacturers using the ECM, none of them take advantage of the motor's ability to control airflow.

The National Sanitation Foundation (NSF) tests and approves Class II biosafety cabinet designs to ensure both a sterile work area and user protection. To become NSF listed a biosafety cabinet's design must conform to ANSI/NSF Standard 49, which outlines acceptable velocities for both inflow and downflow. As the HEPA filters in a biosafety cabinet become loaded with particles and the static pressure rises, the airflow through the cabinet gradually decreases. Routine adjustment and recertification of the cabinet's blower is required to ensure that the air velocity is within the range specified by ANSI/NSF 49.

Before the introduction of the Logic, biosafety cabinets monitored air velocity using airflow sensors(s). However airflow sensors have their limitations, Airflow sensors are susceptible to temperature changes, humidity, and dust particles. In addition, the accuracy of the airflow sensors commonly used in biosafety cabinets is typically only within 5%.