What’s the hardness tester
Publish Time: 2018-04-10 Origin: Site
What’s the hardness tester
With the development of monolithic technology in 1978, Dr. Leeb of Switzerland proposed a new method for measuring the hardness for the first time. Its basic principle is that a certain mass impact body effects the surface of the sample under a certain test force and measures. The impact velocity and rebound velocity of the foam shore hardness testerat a distance of 1mm is from the surface of the sample, using electromagnetic principles induces a voltage proportional to the velocity. The Leeb hardness tester is expressed as the ratio of rebound velocity and impact velocity of the impact body.
Formula: HL=1000*(VB/VA)
Where: HL - Leeb hardness value
VB——bounce speed of impact body
VA——impact body impact speed
2.Usage
It is often encountered surface test pieces in the field work, a variety of surface effects on the hardness test results are different in the case of the correct operation, the impact of the sample surface is in the instant and the plane of the sample, so the general support can know that. However, when the curvature is small to a certain size, the rebounding speed of the impacting body is significantly lower due to the difference in the deformed elastic state of the planar condition, so that the hardness meter is shown to be low. Therefore, it is recommended to use a small support . For specimens with a smaller radius of curvature, it is recommended to use a profiled ring.
3.Range
According to the digital ultrasonic hardness tester principle, as long as the material has a certain degree of rigidity, it can form a rebound, you can measure the exact value of Leeb hardness, but many materials Richter and other standard hardness does not have a corresponding conversion relationship, Leeb hardness tester installed only 9 Material conversion table. Specific materials of shore hardness tester are as follows: steel and cast steel, alloy tool steel, gray cast iron, ductile iron, cast aluminum alloy, copper-zinc alloy, copper-tin alloy, pure copper, stainless copper.