Object, Instrument, Technology

See also Tuning fork

Picture: Max Planck Institute for the History of Science

Image
“Tuning Fork Collection Ii, Detail 1”. n.d. Berlin.
Object, Instrument, Technology

The vibration microscope is an electromagnetically-driven adaptation by Hermann von Helmholtz (1821-1894) of the earlier optical comparator by Jules Antoine Lissajous (1822-1880). The device allows one to determine the frequency of a tuning fork or other vibrating object with respect to a fork of known frequency, by way of Lissajous figure analysis.

Object, Instrument, Technology

Wooden sticks, when dropped on the floor, sound a variety of tones. While the bars of a xylophone are varied in tone by changing their length, these “tone bars” are all of the same length and width, but have different thicknesses and different densities and elastic properties.

Object, Instrument, Technology

The Case Collection of Physics Instruments (CCPI) has several dozen forks mounted on resonance boxes (see Fig. 1).

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“Tuning Fork Collection Ii, Detail 6”. n.d. Berlin.
Object, Instrument, Technology

See also Tuning fork

Picture: Max Planck Institute for the History of Science

Object, Instrument, Technology

Helmholtz described in his 1862 [sic] book, On the Sensations of Tone, an apparatus able to pick out specific frequencies from a sound. The Helmholtz resonator, as it is now called, consists of a rigid container of a known volume, nearly spherical in shape, with a small neck and hole in one end and a larger hole in the other end to admit the sound.

Object, Instrument, Technology

Date of production: 1950s

Image
“Brüel & Kjær 2304 Level Recorder (1)”. n.d.