SlimLine 9173B, Instruction Manual

Page: 22 / 44

SlimLine Force Sensor, Type 9173B to 9177B
Page 20 9173B_002-286e-07.10
6. Calibration and Maintenance
The SlimLine quartz force links Types 9173B… to 9177B…
are reliable instruments needing virtually no maintenance.
Please read the following two sections to ensure reliable
long-term operation.
6.1 In-Situ Calibration of Force Sensors
Absolute measurement results can only be achieved if the
complete measurement assembly, e.g. the preloaded load
washer and its mounting fixtures, has been calibrated.
If it is possible to remove the force measurement assembly,
without influencing the preload and load distribution of the
force sensor, the assembly can be sent to a Kistler Calibra-
tion Center for recalibration. If, however, the sensor is in-
tegrated into the machine structure, it normally is not pos-
sible to remove the force measurement assembly for recali-
bration. In this case an in-situ calibration must be per-
formed.
6.1.1 Working Point Calibration by Peak Value Comparison
The test system is calibrated by comparing its output with
that of a reference measurement chain at loads around a
specific working point. An average sensitivity is calculated
from the peak values of both the reference and test sys-
tems recorded over multiple load cycles.
It is important to note the calculated sensitivity, S*, is valid
for a specific measurement chain, i.e. sensor, charge ampli-
fier and display unit. Exchanging sensors or amplifiers will
make the calibration invalid.
Furthermore, the sensitivity S* is calculated around a spe-
cific working point and will invariably differ slightly from
any works calibration results, which would have been de-
rived using a standard continuous calibration procedure. It
is generally also recommended to check the distribution of
the average sensitivity by calculating the standard devia-
tion of the sensitivity S*.