Schmidt ETB, Operating Instructions Manual, Page: 14 / 24

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3.7 Static Verification of Measuring Accuracy
All tension meters are calibrated with standard materials - such as polyamide monofila-
ment (PA) - according to the SCHMIDT factory procedure. The diameters are given in
Chapter 2.
Any difference in process material size and rigidity from the standard material may cause
a deviation of the accuracy.In 95% of all industrial applications, the SCHMIDT calibration
has been proven to provide the best results and is used for comparative purposes.
Requirements
:
- The ETB is factory calibrated for a vertical material path (fig. 3.7).
- Tension meter switched on as described in Chapter 3.3.2.
- The required reference weight must be provided.
The tension meter has been calibrated dynamically according to the
SCHMIDT factory procedure.
Therefore, differences may occur between static and dynamic readings.
Verification procedure
:
- Hang a weight which
corresponds to the tension to
be measured (pay attention to
the correct unit of measure cN)
from the measured material,
vertically, as shown in fig. 3.7.
- Press the LEVER down all the way.
- Thread the process material through the MEASURING-
and GUIDE ROLLERS as described in Chapter 3.4.
- Slowly release pressure on the LEVER until the GUIDE ROLLERS return to their
original position.
- Before starting the calibration, move the instrument slowly up and down to compensate
for possible mechanical friction losses and thus ensure repeatability of the
measurements.
- The tension value shown on the DISPLAY should be equal to the value of the suspended
weight (Pay attention to the measuring units).
If this procedure shows a deviation, you can recalibrate the instrument following the
directions in Chapter 3.9.
3.6 Error Messages
(Cont.)
Error message 2
:
- The DISPLAY shows
-E E
.
cN
.
The lower limit of the tension range was fallen below by more than 10%.
Properly insert the process material.
OR
AUTO ZERO is no longer possible.
Recalibrate the instrument following the directions in Chapter 3.9.
MEASURING- and
GUIDE ROLLERS
fig. 3.7
Process
material
Weight