FISCHER FISCHERSCOPE X-RAY XDLM 231, Operator'S Manual

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Why monitor measurement devices? Measurement device monitoring for the Fischerscope X-RAY
FISCHERSCOPE
®
X-RAY 109
15.2 Why monitor measurement devices?
Stability
In the course of time, each coating thickness measuring instrument
changes due to wear and drift. Long-term, this also changes the
measurement applications and calibrations, and thus, the
measurement readings. The resistance of an instrument to long-
term changes is called
stability . Each user is interested in a high
stability of his instrument.
To determine the long-term behavior of the instrument and its
measurement applications, the user checks in regular intervals and
if required, takes corrective action. These measures are essential
for measurement device monitoring. Measurement device
monitoring secures the trueness of the measurements permanently.
As long as a measurement application does not change or if it is
always corrected on time, the calibration and thus the measurement
readings of the measurement application will remain correct.
However, a measurement application can also produce wrong
readings due to erroneous operation, e.g., changing the
measurement parameters, wrong or improper calibration or faulty
measurement conditions. This too can be recognized and remedied
by measurement device monitoring.
The user has the duty to check and monitor each individual
measurement application in the instrument, not only the instrument
as a whole. The instrument manufacturer cannot satisfy this task.
He may provide a calibration service but cannot continuously pay
attention to the trueness of the measurements. The basic
requirements of measurement device monitoring are that they are
carried out regularly and that they are documented. Thus,
measurement device monitoring is a task of the user who should
delegate this task to a trustworthy person with sufficient expertise.
The calibration standards are also measurement devices and
therefore subject to monitoring. However, they change very slowly,
generally through wear and tear during use, more rarely through
structural changes, e.g., diffusion or corrosion. In contrast to the
instrument, the user will not be able to carry out the measurement
device monitoring for the calibration standards. We recommend to
treat the standards gently, to store them according to instructions
and to have them
tested or re-certified regularly, e.g., once a year.
Certified calibration standard sets or so-called application kits are
available for most of the typical measurement applications. They
are necessary to verify the trueness of the measured values in
cases of dispute and to minimize product liability risks.