Breckland Scientific 2023 Catalogue

Gas

Properties of Gas

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1 COLLAPSING CAN Cylindrical steel can with metal insert and screw- on lid, for demonstrating the ‘collapsing can experiment’. Changes in air pressure on opposite sides of a vessel can be demonstrated by placing a small amount of water in the bottom of the can and heating it until properly boiling (using a Bunsen flame or hotplate). Remove from the heat then push the insert (supplied) into the opening of the can and screw the lid on tightly. As the vapour inside the can cools and decreases in volume, the resulting lower pressure causes the can to implode, due to the higher air pressure on the outside. A simpler method would be to place a 1-hole rubber stopper with tube inserted into the opening and connect the other end of the tube to a vacuum pump. As the pressure inside the can decreases, the higher pressure on the outside of the can will cause it to implode or ‘collapse’. Supplied with lid and insert. Cat No. Description Price Per HPG-300-100 Collapsing Can 3.80 ea. 2 MANOMETER Glass manometer with built-in stopcock, mounted on a backing plate. Scale 80-0-80 mm, with 2mm subdivisions. Backplate dimensions: 400 x 80mm. Cat No. Description Price Per HPG-650-100 Manometer, Mounted 33.88 ea. 3 HYDRAULIC PRESS Comprises a pair of graduated glass syringes of capacities 50 and 20cm 3 , both having finely ground pistons and providing a cross-sectional area ratio of 3:1 respectively. Both the syringes have loading platforms on their tops. A 3 way tap allows the syringes to be opened to the atmosphere, isolated or interconnected as desired. Both the pistons provided with limit-stop to prevent their complete ejection from the barrels. The thick walls of the syringes allow them to be capable of withstanding the pressures involved. Cat No. Description Price Per HPG-450-100 Hydraulic Press 130.69 ea. 4 MAGDEBURG HEMISPHERES - STANDARD Simple apparatus used to demonstrate the force of atmospheric pressure. Consisting of two tough plastic hemispheres, with a rubber O-ring to form a seal between them, each half having a strong handle to pull on. One hemisphere also includes a stopcock, which is opened to allow the air inside the connected halves to be pumped out using a vacuum pump, creating a near vacuum inside, before being closed again and the pump removed. The stopcock is also used to release the vacuum, to allow air back inside. With the air removed from inside the hemispheres they become extremely difficult to pull apart, due to the force of the atmospheric air pressure on the outside. Hemisphere diameter, approx. 100mm. Can be connected to any suitable vacuum pump for evacuation - see ‘Pumps’ section. Cat No. Description Price Per HPG-600-100 Standard Magdeburg Hemispheres 34.03 ea. 5 MINI MAGDEBURG HEMISPHERES These mini-Magdeburg hemispheres demonstrate the force of air pressure without the need for a vacuum pump. In this modern variant of a famous 17th-century experiment, students place the faces of two hemisphere cups together and squeeze them, forcing out the air between them. Pulling the cups apart is then surprisingly difficult due to the lack of air pressure between them. Each of the 7.5 cm diameter rubber hemisphere has a 2-finger tug handle and 2 release knobs. Cat No. Description Price Per HPG-580-100 Mini Magdeburg Hemispheres 9.91 pr

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Collapsing Cans

Manometer

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Hydraulic Press

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Standard Magdeburg Hemispheres

Mini Magdeburg Hemispheres

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