Hardness Testing
Hardness is a measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex.

Indentation hardness measures the resistance of a sample to material deformation due to a constant compression load from a sharp object; they are primarily used in engineering and metallurgy fields. The tests work on the basic premise of measuring the critical dimensions of an indentation left by a specifically dimensioned and loaded indenter.

Tetebrineller Method:
The specimen under test is examine by leaving an impression on the surfaces of both the specimen and the standard bar, these impressions are measured by a microscope the diameters are between 3.0 to 4.0 millimeters. The BHN Brinell Hardness Number is calculated by measuring both impressions and entering the data on the Telebrineller computer.

Ultrasonic-Contact-Impedance (UCI) Method:
The hardness is measured by detecting frequency shift of a longitudinal oscillating rod with a Vickers diamond indenter. The small indentation are not measured optically as is usually done rather the indentation area is electronically detected by measuring the frequency shift. The shift is proportional to the size of the Vickers indentation. The electronic unit can convert measurements from Brinell, Vickers, Rockwell B, Rockwell C Hardness, and tensile strength.

Applications are on machined surfaces, thin layers, hardness progression, and tight areas.

Both of these portable units can be used in the laboratory, office, field, factory and shop.