System Sensor ST-3 Tube

The System Sensor ST-3 is a professional-grade metal duct sampling tube engineered for precise air monitoring in commercial and industrial HVAC systems. Designed for duct widths from 2 ft to 4 ft, this 3-foot rigid tube facilitates the intake of air into the detection chamber to ensure rapid smoke identification. This duct smoke detector accessory is specifically built for integration with legacy duct smoke detector models, including the DH100, DH200, DH400, and DH500 series. Its durable metal construction provides superior structural integrity compared to plastic alternatives, especially in high-velocity airflow environments. Proper installation requires the air inlet holes to face directly into the airflow, ensuring the pressure differential remains within manufacturer specifications for reliable sensor activation.

• Compatible with System Sensor legacy detectors: DH100, DH200, DH400, and DH500.
• Optimized for 2-foot to 4-foot duct widths to provide representative air sampling.
• Constructed from heavy-duty metal for long-term durability in harsh HVACR environments.
• Easy-lock mechanism allows for secure front or rear installation and removal without specialized tools.
• Essential for fire life safety compliance in air handling unit (AHU) monitoring.

Which duct smoke detectors work with the ST-3 sampling tube?
The ST-3 is designed for legacy System Sensor units, specifically the DH100, DH200, DH400, and DH500 series. For newer InnovairFlex models, the DST series is typically utilized.

How should the sampling tube be oriented during installation?
For accurate smoke detection, the tube must be installed with the intake holes facing the upstream air flow. If the tube is 3 feet or longer, it is recommended to support the end opposite the detector to prevent vibration or sagging.

Can this tube be cut to fit a smaller duct?
While the ST-3 is rated for 2' to 4' spans, technicians often cut sampling tubes to size. However, the tube should extend at least 2/3 across the duct width to ensure a proper air sample is captured.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.