Knoop hardness number


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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 hard·ness num·ber

(nūp hahrd'nĕs nŭm'bĕr)
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 hard·ness num·ber

(KHN) (nūp hahrdnĕs nŭmbĕr)
Measure; used to measure hardness of any materials, especially very hard and brittle substances, such as tooth dentin and enamel.
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References in periodicals archive ?
All composites showed reduced KHN (Knoop hardness number) after ethanol immersion (Figure 1).
An average of the five measurements was calculated on each surface and transformed in Knoop hardness number (KHN) using the following formula: