Berthon dynamometer

Berthon dynamometer

[′bər‚thän ‚dī·nə′mäm·əd·ər]
(engineering)
An instrument for measuring the diameters of small objects, consisting of two metal straightedges inclined at a small angle and rigidly joined together; a scale on one of the straightedges is used to read the diameters of objects inserted between them.