There are different types of Audible/Visual (AV) indicator systems used on fume hoods at Carleton University. Your fume hood might have one of the indicators listed below. These indicators have an audio and/or visual indicator which alerts laboratory personnel if there is insufficient airflow in the fume hood or laboratory ventilation equipment.
There are four different indicators installed on fume hoods around campus:
- Active Devices
- Plastec, Alnor, Landis & Gyr and Phoenix Face Velocity Monitors:
- Face velocity indicator with an audible and/or visual alarm if the face velocity goes below or exceeds a safe level.
- Vent Alert Monitors:
- Air flow indicator with an audible and/ visual alarm if the air flow goes below or exceeds a safe level.
- Hoffman Air Flow Monitors
- Green indicator light for normal operation.
- Red indicator light and audible alarm when the velocity goes below or exceeds a safe level.
- Plastec, Alnor, Landis & Gyr and Phoenix Face Velocity Monitors:
- Passive Devices:
- Magnehelic:
- Qualitative flow indicator only. The gauge should read greater than 0.1 inches of water.
- Magnehelic:
When an AV system indicates a problem with the fume hood or ventilation equipment:
- Stop all processes, close all chemicals bottles and remove to an appropriate storage area.
- Contact EHS at X3000
- Do Not simply press the silence button on the AV indicator and continue working. You may expose yourself and others to hazardous chemicals.