Development and manufacturing of non-
destructive testing equipment and system
Hardness tester NOVOTEST T-UD3
10
7.2. Choice of the measurement method.
7.2.1. Rebound method of measuring hardness is appropriate for:
- testing objects weighing more than 5 kg and a wall thickness more
than 10 mm;
- massive products, products with a coarse-grained structure, forged
and cast products;
- testing objects with minimal preparation of the surface.
7.2.2. UCI method of measuring hardness is appropriate for:
- testing objects with low mass and small wall thickness;
- testing objects with a glossy surface (with special requirements to
the minimum size of the imprint);
- surfaces of the testing objects with hardened layers.
8. Operation
8.1. Preparation of the test material.
The surface must be clean and free of oil, grease and dust.
The surface roughness of the material should meet the requirements
of a specific probe (paragraph 3.8).
8.2. Features of the methods of measurement of metal hardness:
8.2.1. UCI method:
Distinct reading variations may especially occur with a mass lower
than 0.1 kg and a specimen thickness of less than 1 mm if the test
material is excited to resonance or sympathetic oscillations.
Otherwise, such test materials must be fixed to a solid base, e.g.
using a viscous paste. The same applies to the hardness test
blocks.
