Branson Krautkramer MIC 10, User Manual

Page: 126 / 146

12.3 Preparation of the test material
In order to achieve reliable and repeatable measure-
ment results it is important that you observe the infor-
mation on quality and preparation of the material.
Therefore, read the following information.
Surface finish
The surface must be clean and free of oil, grease and
dust.
The surface roughness of the material must be small
in relation to the penetration depth of the Vickers dia-
mond (ca 14 to 200 micrometers). We recommend a
surface roughness of approx. 30 % of the penetration
depth..
–
Grind rougher surfaces with the grinding device
MIC 1060 (refer to chapter 2.3).
Measuring small test pieces
Distinct reading variations may especially occur with a
mass lower than 0.3 kg and a specimen thickness of
less than 15 mm if the test material is excited to reson-
ance or sympathetic oscillations. Therefore, such test
materials must be fixed to a solid base, e.g. using a vi-
scous paste. The same applies to the hardness refer-
ence plates.
Thin plate must have a thickness which corresponds
to 10 times the penetration depth of the Vickers dia-
mond (see table on the next page).
0
Note:
As per DIN 50133 (hardness measurement according
to Vickers) the center distance between two neighbour-
ing indents in relation to the mean length of the indent
diagonal must be
- at least 3 times the amount for steel, copper and cop-
per alloys,
- at least 6 times the amount for light metals, lead, tin
and their alloys.
If two neighbouring indents vary in size then the mean
indent diagonal of the larger indent must be used for
calculation of the minimum distance.
Appendix
Preparation of the test material
12-4 Issue 08, 08/01 Krautkrämer MIC 10
12.3 Preparation of the test material
In order to achieve reliable and repeatable measure-
ment results it is important that you observe the infor-
mation on quality and preparation of the material.
Therefore, read the following information.
Surface finish
The surface must be clean and free of oil, grease and
dust.
The surface roughness of the material must be small
in relation to the penetration depth of the Vickers dia-
mond (ca 14 to 200 micrometers). We recommend a
surface roughness of approx. 30 % of the penetration
depth..
–
Grind rougher surfaces with the grinding device
MIC 1060 (refer to chapter 2.3).
Measuring small test pieces
Distinct reading variations may especially occur with a
mass lower than 0.3 kg and a specimen thickness of
less than 15 mm if the test material is excited to reson-
ance or sympathetic oscillations. Therefore, such test
materials must be fixed to a solid base, e.g. using a vi-
scous paste. The same applies to the hardness refer-
ence plates.
Thin plate must have a thickness which corresponds
to 10 times the penetration depth of the Vickers dia-
mond (see table on the next page).
0
Note:
As per DIN 50133 (hardness measurement according
to Vickers) the center distance between two neighbour-
ing indents in relation to the mean length of the indent
diagonal must be
- at least 3 times the amount for steel, copper and cop-
per alloys,
- at least 6 times the amount for light metals, lead, tin
and their alloys.
If two neighbouring indents vary in size then the mean
indent diagonal of the larger indent must be used for
calculation of the minimum distance.
Appendix
Preparation of the test material
12-4 Issue 08, 08/01 Krautkrämer MIC 10