XGard ASU The ASU enables Xgard gas detectors to monitor toxic or fl ammable gases within ventilation ducts without subjecting the detectors to high air velocities which could affect the sensor. Features Fully specifi ed performance between 5m/s and 20m/s ducted air fl ow Sampling probes suitable for ducts from 300mm wide Strong, lightweight and compact design Supplied with all fi ttings necessary for one Xgard detector • • • • Installation aid for accurate and easy fi tting Colour coded inlet and exhaust probes Minimum effect on ventilation system functioning. Sensor can be calibrated/replaced without opening the duct. • • • •

The Crowcon air sampling unit works by taking a sample of air from the duct through a black perforated inlet probe into its sampling chamber. The air is exhausted back into the duct through a white probe. The design of the probes and sampling chamber is arranged so that air passes through the sampling chamber at approximately 25% of the air speed in the duct. The ASU consists of a grey polycarbonate box fi tted with a transparent polycarbonate cover. The transparent window which has a built-in sealing gasket can be removed by undoing four screws to provide access during installation or maintenance....