Operator‘s Manual FERITSCOPE
®
FMP30
Page 221
Glossary
If, for instance, the same number of measurements is performed on sev-
eral specimens and the readings on each object are combined into a
block (e.g., when making measurements with a fixed block size), s. is a
measure for the instrument deviation and sa is the product deviation with
the instrument deviation eliminated.
sII
Deviation of the block mean value around the overall mean value sII is
calculated as follows:
where:
sII
= deviation of the block mean values
N
Bl
= Number of evaluated blocks
N
i
= block size (number of readings per block)
Fe..
= mean value of the block mean values
Fe.
j
= block mean values
Estimated value for the standard deviation
of the population.
where: = estimated value for the standard deviation
of the population
s. = mean standard deviation
c
4
= The factor c
4
depends on the random sample size and can be obtained
from popular published tables, e.g., / 4 /.
Sigma outlier rejection
Significant surface
Area on the surface of a specimen containing the
-ferrite content to be
measured. All properties necessary for the use and appearance of the
product must occur at this significant area.
Single reading
Measurement result that is displayed or printed after a single measure-
ment at the measurement location.
Skewness
Measure for the asymmetry of a single-peak probability distribution
around its mean value. A positive skewness indicates a distribution
whose peak stretches more towards values that are greater than the
s
II
N
i
1
N
Bl
1
–
------------------
Fe.. Fe.
j
–
2
j
1
=
N
Bl
=
ˆ
s.
c
4
-----
=
ˆ
