Ultrasonic contact impedance hardness testing is a non-destructive, easy-to-use method for measuring the hardness of metallic samples. It complies with ASTM A1038 and offers mass storage capabilities, simple calibration, and quick measurement techniques that are conducted in less than 2 seconds.
A mechanical resonator with a Vickers diamond at its end is vibrated in contact with the test material. The resulting frequency change df is measured and the hardness value HV is derived immediately.
The UCI method is a quick, non-destructive test that is used for determining comparative hardness values. It is ideal for weld inspection, control of metal coatings, and measuring the hardness of products with difficult-to-access surfaces or structures.
The measuring principle is similar to that of the classic Vickers test: a pyramid-shaped diamond is forced into the material by spring pressure and the resulting indentation area is measured by electronic measurement of the frequency shift. This value is then converted to a hardness value.
The device adjustment to materials with deviate from Young’s modulus of elasticity is very simple and only needs to be carried out once, because the adjusted hardness value (HVUCI) and the stored material tables from EN ISO 18265 or ASTM E 140 already contain the adjustment numbers. This significantly simplifies the work procedure for your operators and improves reproducibility. The large LCD display and simple calibration further enhance the user-friendliness of this mobile hardness tester.
UCI testers are used to quickly measure the hardness of small forging, cast material, weld inspection, heat affected zone, Ion-nitride stamping dies and molds, forms, presses, thin-walled parts and bearings or tooth flanks. These devices are easy to use and can be programmed with an interactive interface, a range of statistical functions and additional scales.
As with traditional Vickers testing, the UCI method uses a diamond probe on the surface of the test specimen to indent it. The frequency of the mechanical resonator (vibrating rod) changes upon contact with the material, and the resulting measured value represents the material’s hardness.
This method is non-destructive and allows for the measurement of difficult-to-reach locations or challenging geometry. This makes the device ideal for applications that require a large number of inspections, such as incoming goods or quality assurance during production. These tests can also help to save money on waste due to product or structural failure, as they reduce the need for expensive rework.
While mobile hardness testers can be used for many applications, they are only useful if guidelines or specifications are available and the material properties are known. Moreover, possible (constant) influences on the device by probe guidance and mounting must be compensated for. Especially for metals with a deviating modulus of elasticity, a UCI calibration is therefore recommended.
Using the UCI method, you can measure the hardness of metals without damaging the test object. The measurement system uses a vibration sensor rod with a Vickers diamond at its tip that is indented into the test object. This generates a frequency shift which is measured and converted into the hardness value.
The mobile UCI hardness tester NOVOTEST T-U2 fills a significant gap in the field of non-destructive testing. It is ideal for measuring small items, objects with thin walls or a complex form and for surface-hardened coatings. UCI is also suitable for the measurement of the hardness of gear teeth and saw blades or various metal fasteners when the application of a Leeb probe is unsuitable or requires an additional operation.
UCI Hardness Tester T-U3
The UCI Hardness Tester T-U3 is used for the contactless ultrasonic measurement of surface-hardened layers and can be operated in tight spaces. The device has a variety of cable-connected probes with different test forces. Depending on the test area and object geometry, there are hand-held probes with the standard test load of 10 N, motorized measuring sensors with 49 N or 98 N and a tripod.
A comparison of the measured values in real-time is possible on the large full-color display and enables operator errors to be eliminated. The comparison can also be displayed as a graph. The user can choose from 88 combinations of metals and hardness scales, and create their own material tables for the optimum evaluation of the results.
The instrument can be calibrated quickly and easily with a sample of known hardness (for plus/minus testing) or by using 2 reference blocks of the same material with different hardness values. In addition, the UCI is equipped with several user calibration fields for steel, nonferrous metals, alloys and other materials, and has two custom fields for conversion to other scales.