Honeywell System Sensor DST3 Sampling Tube 36 in

Sampling tube for duct detection

The Honeywell System Sensor DST3 is a metal sampling tube designed for use with compatible duct smoke detectors in commercial HVAC systems. It draws air from the airstream into the detector chamber for early fire warning. Installers select this accessory when a duct-mounted detector requires a rigid probe that spans the duct width.

Fits ducts two to four feet wide

The tube length is 36 inches and the depth and height are each one inch, allowing it to sit flush against the duct exterior once mounted. It connects directly to the detector mounting base without additional brackets, leaving the interior airway clear for uninterrupted airflow sampling. The metal finish resists corrosion in typical plenum environments.

Covers ducts up to four feet across

At 36 inches the probe reaches the centre of the maximum specified duct width, giving the detector representative air samples across the full cross-section. In ducts wider than four feet the tube cannot extend far enough, so a longer probe or alternative detection method would be required.