Accessory part for electric vibrator 218500. The plate may be included in experiments intended to demonstrate the sound patterns produced at different frequencies.
The experiment is carried out by sprinkling a thin layer of fine sand over the plate and sounding figures ("Chladni" figures) will appear when the oscillation frequency is set. During the experiments, plate resonances can also be heard.
The plate is made of lacquered iron and is square with 140 mm. pages. The mass of the plate is 150 g.