Knoop hardness test
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Knoop hard·ness num·ber (KHN),
(nūp),a number obtained by dividing the load in kg applied to a pyramidal diamond of specific size divided by the projected area of the impression: KHN = L/A, where A= the projected area of the impression in mm2 and L = the load in kg; used for measurements of hardness of any materials, especially very hard and brittle substances such as tooth dentin and enamel.
Knoop hardness test
[no̅o̅p]
Etymology: Frederick Knoop, 20th century American metallurgist
a method of assessing surface hardness by measuring resistance to the penetration of an indenting tool made of diamond. The test is commonly used for testing the hardness of teeth.
Knoop hardness test
(noop),KHT
A test of surface hardness, using a stylus with a pyramidal diamond indenter. The long diagonal of the resulting indentation determines the hardness of the substance.
Knoop hard·ness test
(knūp hahrdnĕs test)Dental measurement to determine hardness of brittle materials; uses a diamond or rhombic indenting tool; test result provides dental clinicians with the Knoop hardness number.