11
Weight
Guide rollers
Measuring roller
Material thickness
compensator
Process material
Scale
fig. 3.4
- Suspend a known weight that corresponds to the tension to be measured (pay
attention to the correct unit of measure) from the Process material, vertically, as
shown in fig. 3.4. (Always use a fresh portion of the material to be measured).
- Push the thumb piece as far as it will go in the direction indicated by the arrow and
thread the material to be measured between the guide rollers and the measuring
roller. Refer to Chapter 3.3.
- Slowly release pressure on the thumb piece until the outer rollers return to their
original position.
- Before the final check, move the instrument slowly up and down to compensate any
friction caused by the instrument and thus ensure the repeatability.
- The tension value should be equal to the value of the suspended weight.
If this procedure shows a deviation beyond the allowable tolerance and a reliable
operation is no longer allowed, the instrument has to be recalibrated or repaired.
For recalibration, return the tension meter to the factory.
Requirement:
If necessary, a sample of the material to be measured must be
inserted in the thickness compensator as described in Chapter 3.2
All tension meters are calibrated with standard materials - such as polyamide
monofilament (PA) - according the SCHMIDT factory procedure.
The filament sizes are noted 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.
If the process material differs significant in size, rigidity and shape we recommend
special calibration using customer`s sample. For this purpose a material sample of 5 m
should be supplied.
Checking procedure
:
3.4 Verification of the DN1 calibration
It is essential that the thumb piece return slowly to its initial position.
Any uncontrolled snap-back may affect calibration and may also damage
the instrument.
