Appendix
NewSonic SonoDur-R
Issue 105 06/2020
Page 81
11.5
Formulas and Designations
In
Chapter 7.7
"Info-Menu", the calculation results are shown, which are explained in more detail
here (also refer to EN ISO 18265).
The mean value in Fig. 11.1 is X with overlined Beam here referred to as "Xquer".
Xquer =
𝟏
𝑵 ∗ ∑ 𝑿(𝒊)
𝑵
𝟏
(1)
With X (i) = individual hardness value, N = total number of measurements
If no hardness progression measurements are carried out, the mean value is usually the
characteristic measure for the hardness of a material or for a specific test position at the test part. By
averaging, operator influences and/or influences due to material inhomogeneity can be reduced
(exceptions are strongly heterogeneous materials such as GG or GGG cast iron, for example).
R = range/span or maximum error of a series of measurements
R = X(Max)
–
X(Min)
(2)
NOTE:
The relative span is calculated according to EN ISO 18265 depending on the selected scale:
R [%] =
___
R___
Xquer
* 100
(for HV, HB, HK, MPa)
(3)
R [%] =
______
R ____
100 - Xquer
* 100
(for HRC, HRA, HRD, HRN)
(4)
R [%] =
______
R_____
130 - Xquer
* 100
(for HRB and HRF)
(5)
Figure 11.2
