Spherometer

The spherometer consists of a central steel support with an inset screw, which forms a sppike of variable height (1mm scale) and a rotaing disk fixed vertically to the screw, with graduations to measure the height of the disk on a 1/100 scale. Adjusted to the support are three spike-shaped legs at equal angles of 120degrees.

Functioning:
Used to measure the radius of curvature of an extended object, for example a lens, to reasonable precision. The vertical scale is used as a height measurement for the screw (with the disk as a marker), and the graduations on the disk as a fine-resolution device for the same measurement, to fractions of a revolution. Adjustment of the screw, to place all four legs on the surface, allows calculation of the radius of curvature from the height measurement and the dimensions of the device.

Data

Inventory Number: 

MES03

Date: 

1875 (c.)

Dimensions: 

Base length : 19cm, Height : 24cm

Materials: 

Steel, Brass

Instrument Categories: 

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