Polytec TMS-350 TopMap In.Line, Руководство по оборудованию

Страница: 51 / 59

A-7
A TMS-A-305 Calibration Set
Evaluation
method
The Add-in calculates the depth of the grooves according to the evaluation
method defined in the calibration certificate:
•
The ambient temperature determined is used to reduce the groove depth
to 20°C. This means that the groove depth is calculated which would
result if the depth setting standard were measured at a temperature of
20°C. The linear thermal expansion coefficient of
specified in the calibration certificate is used. A temperature difference of
3 K (Kelvin) for example with the 200 µm groove results in a thermal
expansion of 10 nm. To determine the expanded measurement
uncertainty, an uncertainty of the temperature determination of 2 K is
assumed.
•
The values calculated by the macro are displayed in the profile view
legend.
The following values are shown for each of the grooves evaluated:
The expanded measurement uncertainty displays the statistic uncertainty of
the calibration. It takes into account the uncertainty of the standard as well as
the uncertainty of the measurement. The expanded measurement uncertainty
is determined according to the "Guide of the Expression of Uncertainty in
Measurement" (ISO, 1995, German version DIN V ENV 13005:1999).
To calculate the expanded measurement uncertainty, four parameters are
taken into account:
•
The expanded measurement uncertainty of the standard indicated in the
calibration certificate,
•
An assumed uncertainty of 1 K when determining temperature of the depth
setting standard,
•
The standard deviation of the evaluations of the single profile sections,
•
The influence of the uncertainty of the markers determined 1-6 (see
calibration certificate) on the measurement result.
Groove 1, groove 2,
…:
For every groove, the measured groove depth
reduced to 20°C (average of 6 profile sections)
Calibration: The groove depth according to the calibration
certificate
Difference: Deviation between the measured groove depth and
that according to the calibration certificate
Expanded
uncertainty:
Expanded measurement uncertainty (confidence
level 95%)
Sum: The sum of the deviation between the measured
groove depth and that specified in the calibration
certificate, and the measurement uncertainty
Tolerance This tolerance is specified for the device for the
respective groove.