ST280 Sampling Tube

Calectro’s ST280 sampling tube for UG8 Duct Detector

£9.50£11.40 inc. VAT

20 in stock

Manufacturer part number: ST280
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Sampling tube compatible with the venturi tubes from the ST series, for Uniguard 8 detectors (

To detect, and also prevent, smoke from spreading in ventilation ducts it is crucial that the smoke detection system has access to high-quality air samples. An air probe in the form of a tube, also called a venturi tube, is an effective way of continuously collecting samples of air. By using the air flow in the ventilation duct, high and low air pressure is created in the venturi tube. That allows the venturi tube to provide air samples perfect for analyzing potential hazardous particles.

The aerodynamic design of the housing and the tube are crucial in order to detect small levels of smoke particles in the air at an early stage. The tube collecting air samples from the duct, also known as a venturi tube, is based on the Venturi effect. The Venturi effect is named after the Italian physicist Giovanni Battista Venturi (1746–1822). The Venturi effect is a reduction of air pressure as a result of air flowing at an increased velocity through a constricted section of a tube. Thus, the only thing a venturi tube needs to function is air flow in the ventilation duct of at least 0,2 meters per second. There are no pumps or mechanics attached to the tube that require energy. It does not generate any noise and there is no wear on the tube that might require service.

Calectro’s smoke detection system called Uniguard has a patented venturi tube which consists of three separated channels combined into one larger tube, formed as a triangle. Each channel is fitted with an aerodynamic slit. When the airflow hits the front channel, it creates a high air pressure, which pushes the air to the smoke detector. When the air in the ventilation duct passes on each side of the tube, where the other two channels are located, the speed of the air increases which leads to low air pressure (the venturi effect), helping to draw the air back from the smoke detector to the ventilation duct.

The design of Calectro’s venturi tube, with two channels creating low pressure instead of one, has been engineered in detail and gone through multiple tests to deliver the best possible result. We found that this is the most effective way of drawing air from the depths of the entire ventilation duct and delivering it to the smoke detector. Our design facilitates the discovery of hazardous particles even in small doses and at very low airflows.

Length 280mm.

Made in Sweden

Additional information

Weight 0.5 kg
Unit colour




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