Ultrasonic Contact Impedance Hardness Testing

Mobile UCI hardness testing devices use a manual or motor measurement probe to contact the test sample. The resulting test impressions are assessed digitally and automatically saved.

This makes them ideal for incoming goods inspection, mix-up checks or production control. UCI testing is also non-destructive, meaning you will save time and money compared to traditional hardness tests.

High Accuracy

Unlike traditional rebound testers that measure the diameter of the restored indentation, ultrasonic contact impedance hardness testing relies on measuring the frequency of the indenter-free oscillations. This enables portable testers to achieve high levels of accuracy – with the added benefit that conversion to different hardness scales is possible in real time.

The UCI method makes it possible to determine hardness values in locations that are difficult to access with a Leeb probe, especially for small items with complex shapes and thin wall. It is also ideal for measuring the hardness of surface-hardened layers.

Large LCD Display – Directly displays measurement results, test time count, maximum, minimal and average and deviation. Simple Calibration – Saves up to 20 groups of calibration data for invoking, improving calibration efficiency. The UCI method complies with the main hardness scales. This includes HB, HRC and HV. The measurement range is suitable for the whole material spectrum, from soft to very hard.

Simple Calibration

Many portable hardness testers require extensive calibration in a lab with single measurements. This process is very time-consuming and requires expensive equipment.

Qualitest’s UCI-3000 uses the ultrasonic contact impedance method to perform comparative hardness measurements on material samples and provides high accuracy, efficiency and portability. It is ideal for use in fields, workshops and laboratory conditions.

The UCI-3000 measures the comparative hardness of small forgings, cast materials, weld inspection, heat-affected zones, ion-nitride stamping dies and molds, forms, presses, thin-walled parts, bearings, tooth flanks and more. It can measure the hardness of metals and non-ferrous materials using main hardness scales (HB, HRC, and HV).

The UCI-3000’s advanced design offers a mass storage capability for multiple measurement points and an easy-to-use “plug and measure” interactive interface. It also has a wide range of programming functions and additional scales for non-standard probes. This simplifies the calibration and operation processes making it suitable for users without prior experience in hardness testing.

Easy to Operate

Unlike the more complex dynamic impact style test equipment, ultrasonic contact impedance hardness testing uses simple mechanics to measure the test piece. A mechanical resonator with a Vickers diamond at its tip is forced into the material surface, creating a small indentation with a fixed test force. The frequency of the vibration is then measured, and the resulting data is converted into a hardness value by software.

Compared to traditional methods, UCI testers can measure a wide range of materials and hardness values and are much easier to use. The tester can be finely calibrated to a particular metal type, such as steel, or used with the general calibration of the standard scales HB and HRC.

The UCI method is ideal for quick measurement of small fogging, cast material, weld inspection, heat affected zone, Ion-Nitride stamping dies and molds, forms, presses, thin-walled parts, bearings and tooth flanks. It is also ideally suited to taking measurements in difficult positions and challenging component geometries, such as the base of gear teeth.


UCI measuring instruments allow hardness tests to be carried out on difficult test positions and challenging component geometries – something that is not always possible with traditional Vickers testing methods. This opens up many new application possibilities, for example, quality assurance functions during production and inspections of incoming goods, as well as in the case of difficult surface shapes and dark backgrounds.

This is made possible by a non-contact measurement process that does not damage the material. A mechanical resonator is excited to longitudinal vibrations with a frequency of about 78kHz and forced into the test material. The change df in the frequency f of the resonator is measured and the hardness value HV (or modulus of elasticity E) is calculated according to a conversion formula.

This makes the UCI method the ideal supplement to other surface hardness testing procedures. The portable UCI and combined NOVOTEST models are suitable for all common metal materials and for all the most commonly used hardness scales – Leeb, Rockwell C, B, Brinell and Vickers.