Breckland Scientific 2021 Catalogue

Sound & StandingWaves

Resonance

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1 LASCELLS RESONANCE SYSTEM This original apparatus gives students a modern approach to a fascinating topic, with scope for imaginative research. An acrylic base unit supports a hacksaw blade which is loaded at the top with a detachable brass weight. An electromagnetic drive coil, connected to a standard laboratory signal generator can cause the blade to vibrate in various modes. A bimorph, piezo-electric transducer, bonded to the blade, detects the amplitude of the vibration when its output is monitored on a C.R.O. Students can study the amplitude of vibration and resonance as a function of drive frequency. In addition, there is a mechanical damping system provided by a thin aluminium vane moving in a small vessel containing water. The amount of damping is controlled by the depth of water used. The effect of damping on resonance can be studied. Cat No. Description Price Per SWA-165-200 Resonance System 101.18 ea. 2 KUNDT’S RESONANCE TUBE - BASIC Glass tube for demonstrating standing sound waves and calculating wavelengths of sound using cork powder in a method devised by Kundt. Cork powder is spread evenly throughout the tube by means of a filler chute. Then a sound source, e.g. a whistle or a 1700 Hz tuning fork or the speaker below is used to excite the powder into a regular pattern of nodes and antinodes. The effective length of the tube can be altered by means of a piston. Length: 600mm, external diameter: 20mm, internal diameter: 17mm. Supplied with tube, funnel, plunger, filler chute, whistle and bottle of cork powder. Cat No. Description Price Per SWA-100-100 Kundt’s Resonance Tube - Basic 71.07 ea. SWA-100-150 Cork Powder 10.35 10g The main tube is 1 metre long and 50mm diameter with a high power loudspeaker unit plugged in to one end. The loudspeaker is driven by a standard laboratory signal generator and as the frequency is adjusted the various resonance modes are detected by increased loudness of the note. The open pipe can be studied or a variable length closed pipe can be used by inserting the piston assembly provided. By using a higher amplitude on the generator, Kundt’s tube investigations can be undertaken. Fine cork or polystyrene dust is distributed throughout the tube and at resonance the powder gathers at the nodes. Wavelengths can be easily measured. To get a good response a closed tube is preferable, to reduce the sound levels in the laboratory while producing a measurable effect. The apparatus comes complete with two supports for the tube, sound wave generator, resonance tube, closing bung and full instructions. Requires a signal generator. Cat No. Description Price Per SWA-175-100 Resonance Tube 127.70 ea. 3 LASCELLS RESONANCE TUBE This apparatus is ideal for all resonance investigations in air columns. 4 LASCELLS RESONANCE TUBE ACOUSTIC PROBE This sensitive microphone, mounted on a 1.1m long acrylic tube, enables the characteristics of a standing wave in a pipe to be demonstrated. It is particularly suited to the Lascells Resonance Tube. The probe lead plugs into an interface box which provides the signal for display on a CRO or for monitoring on an a.c. voltmeter. As the probe is moved along the tube nodes and antinodes can be clearly shown thus enabling wave calculations to be made very easily. Requires 1 x PP3 9V battery (supplied). Cat No. Description Price Per SWA-175-150 Acoustic Probe for Resonance Tube 71.23 ea.

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Lascells Resonance System

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Kundt’s Resonance Tube - Basic

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Lascells Resonance Tube

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Acoustic Probe for Lascells Resonance Tube

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