Branson Krautkramer MIC 10, User Manual

Page: 125 / 146

12.2 Conversion of hardness values
The conversion of hardness values into other hard-
ness scales is only possible with certain limitations.
Therefore, in the following we give important informa-
tion which you should take into account.
Hardness values which were measured by different
methods cannot be converted to each other on the
basis of generally applicable relationships (see
DIN 50 150 resp. ASTM E 140).
In one respect, the reasons for this are found in the
fact that the penetration behaviour of a material is
determined by its stress behaviour and change of form
behaviour. On the other hand, the form and material of
the indentation diamond, the size of the indent and,
therefore, the measured area vary with the hardness
testing methods used.
Therefore, please note that the conversion of hard-
ness values either into other hardness units or units of
tensile strength may be inaccurate or inadmissible, de-
pending on material, material preparation and surface
finish.
Consequently, you should make conversions only in
cases where:
•
the specified testing method cannot be applied, for
instance, because suitable test equipment is not
available.
•
it is not possible to take the samples required for
the specified testing method.
Special factors of MIC 10
The conversion of the hardness values into other
scales, which you can select on the instrument, is
made according to DIN 50150 or ASTM E 140. There-
fore, all limitations specified in this DIN standard for
the conversion are applicable.
Utmost caution is advised when using the Brinell
scale. Under no circumstances should the MIC 10 be
used for the measurement of materials with coarse
grained structure (e.g. gray castings). Particularly ma-
terials of this kind call for a Brinell measurement.
Conversion of hardness values
Appendix
Krautkrämer MIC 10 Issue 08, 08/01 12-3
12.2 Conversion of hardness values
The conversion of hardness values into other hard-
ness scales is only possible with certain limitations.
Therefore, in the following we give important informa-
tion which you should take into account.
Hardness values which were measured by different
methods cannot be converted to each other on the
basis of generally applicable relationships (see
DIN 50 150 resp. ASTM E 140).
In one respect, the reasons for this are found in the
fact that the penetration behaviour of a material is
determined by its stress behaviour and change of form
behaviour. On the other hand, the form and material of
the indentation diamond, the size of the indent and,
therefore, the measured area vary with the hardness
testing methods used.
Therefore, please note that the conversion of hard-
ness values either into other hardness units or units of
tensile strength may be inaccurate or inadmissible, de-
pending on material, material preparation and surface
finish.
Consequently, you should make conversions only in
cases where:
•
the specified testing method cannot be applied, for
instance, because suitable test equipment is not
available.
•
it is not possible to take the samples required for
the specified testing method.
Special factors of MIC 10
The conversion of the hardness values into other
scales, which you can select on the instrument, is
made according to DIN 50150 or ASTM E 140. There-
fore, all limitations specified in this DIN standard for
the conversion are applicable.
Utmost caution is advised when using the Brinell
scale. Under no circumstances should the MIC 10 be
used for the measurement of materials with coarse
grained structure (e.g. gray castings). Particularly ma-
terials of this kind call for a Brinell measurement.
Conversion of hardness values
Appendix
Krautkrämer MIC 10 Issue 08, 08/01 12-3