Adjustment Of Zero Point / Span - WIKA NWU-1 Serie Mode D'emploi

8. Adjustment of zero point
Adjustment of zero point
The UHP-Transducer NWU-10, NWU-15 and NWU-16 are maintenance free. The transducer
is factory calibrated and does not normally need field adjustment.
For equipment with Ex nA certification, or if operated under nA conditions:

!
Never disconnect the equipment when it is powered!
When calibrating / opening the instrument, it has to be ensured that the

Warning
ambient atmosphere is not explosive.
For verification and adjustment of the zero point, vent the transducer to zero (0)PSI for gage
reference transducers. The potentiometer for the zero adjustment is protected inside the trans-
ducer housing. Use a 0.040" to 0.060" (1 to 1.5 mm) jeweler's screwdriver for adjustment.
Span adjustment is not necessary after zero point correction.
Procedure for Transducer without Side-Access
1. Remove all power to the transducer.
2. Remove the locking ring, on the top of transducer, in order to expose
the zero adjusting potentiometer. Carefully pull the assembly out of the
transducer housing, as far as the internal connector cable will allow.
3. Restore power to the transducer.
4. Vent the transducer to pressureless state. Monitor the output signal,
and adjust the zero screw to 4mA or 0.1V depending on the signal
output. The Zero adjustment screws are both turned in a clockwise
direction to increase the signal or in a counter clock-wise direction to
decrease the signal.
5. Remove all power to the transducer again.
6. Rotate the electrical connector on the transducer housing to
the keyed insertion. After this, replace and hand tighten the
locking ring on the top of transducer.
16 WIKA Operating instructions/Betriebsanleitung/Mode d'emploi/Instrucciones de servicio NWU-1
GB
8. Adjustment of zero point
Procedure for Transducer with Side-Access
1. Turn the grip ring until the access to the
potentiometer is free.
2. Adjust the zero point by means of the
potentiometer in pressureless state.
When doing this, do not contact other
components with the screw driver to
excluse a short circuit in the instrument.
Check the zero point by means of a
suitable instrument. Clockwise rotation
means an upward zero offset,
anti-clockwise rotation means a down
ward zero offset.
3. After this, turn the grip screw until the
access to the potentiometer is closed
again.
WIKA Operating instructions/Betriebsanleitung/Mode d'emploi/Instrucciones de servicio NWU-1
S
GB
17
S