How to Measure Hardness On-site?

Conventional hardness testing machines require the test piece be brought to the testing device; but this is not always possible. Portable testing devices have been developed that permit in-situ hardness measurements.

One popular device measures the frequency shift of a resonating rod with a Vickers- diamond tip, which occurs when the diamond penetrates into the test material by applying a specific test load.

The frequency shift is evaluated and electronically converted to a hardness value displayed on the LCD. The MICRODUR instruments (Krautkramer) work according this method, the so-called UCI (Ultrasonic Contact Impedance) method.

Another well-known principle for portable hardness testers is the rebound method. The DynaMIC and DynaPOCKET (Krautkramer), for example, measure the velocity of a propelled impact body directly before and after the impact onto the test material’s surface. The ratio between both velocities indicates the hardness of the material, which can be converted into different scales by using conversion tables stored in the instrument for different materials.

UCI and Rebound hardness testing with just one instrument!

The brand-new Krautkramer MIC 20 combines the two most successfully applied portable hardness testing principles in one instrument. Whether you want to use the UCI principle or the dynamic Rebound testing method – the MIC 20 offers both possibilities. All you need is just one instrument and all current UCI probes and impact devices can be plugged in and used.