Adjustment Of Zero Point; Maintenance, Accessories; Trouble Shooting - WIKA WU-20 Manual De Instrucciones

8. Adjustment of zero point

„ Open pressure connections only after the system is without pressure!
„ Observe the ambient and working conditions outlined in section 7
„Technical data.
Warning
„ Please make sure that the transducer is only used within the over load
threshold limit at all times!
When touching the transducer, keep in mind that the surfaces of the instru-
ment components might get hot during operation.
Caution
8. Adjustment of zero point
The UHP-Transducers are maintenance free. The transducer is factory calibrated and does
not normally need field adjustment.
For equipment with Ex nA nL marking, or if operated under nA nL condi-
„
!
tions: Do not separate when energised.
Warning
For verification and adjustment of the zero point, vent the transducer to zero (0)PSI for gage
reference transducers. Use a 0.040" to 0.060" (1 to 1.5 mm) jeweler's screwdriver for adjustment.
For instruments with absolute pressure measuring ranges or +/- measuring ranges, a
„
sufficient calibration equipment as well as a vacuum pump are also necessary for the
zero point adjustment.
Span adjustment is not necessary after zero point correction.
„
Procedure
1. Restore power to the transducer.
2. Lift the sticker.
3. Adjust the zero point by means of the
potentiometer in pressureless state.
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.
4. Push the sticker on.
16 WIKA Operating instructions/Betriebsanleitung/Mode d'emploi/Instrucciones de servicio WU-2X
GB
9. Maintenance, accessories / 10. Trouble shooting

9. Maintenance, accessories

Accessories: For details about the accessories (e. g. connectors), please refer to WIKA's
price list, WIKA's product catalog on CD or or contact our sales department.

10. Trouble shooting

Warning
Warning
Please verify in advance if pressure is being applied (valves/ ball valve etc. open) and if the
right voltage supply and the right type of wiring (2-wire/3-wire) has been chosen?
Failure
Output signal unchanged after change
in pressure
No output signal
For further information
No/False output signal
(+49) 9372/132-295
Abnormal output signal or
Abnormal zero point signal
WIKA Operating instructions/Betriebsanleitung/Mode d'emploi/Instrucciones de servicio WU-2X
„ WIKA transducers require no maintenance.
„ Have repairs performed by the manufacturer only.
Open pressure connections only after the system is without pressure!
Take precautions with regard to remaining media in removed transducers.
„
!
Remaining media in the pressure port may be hazardous or toxic!
Remove the transducer from service and mark it to prevent it from being
„
used again accidentally, if it becomes damaged or unsafe for operation.
„ Have repairs performed by the manufacturer only.
Do not insert any pointed or hard objects into the pressure port for cleaning to prevent
damage to the diaphragm of the pressure connection.
Possible cause
Mechanical overload through over-
pressure
Wrong supply voltage or current spike
No/incorrect voltage supply or current
spike
Cable break
Incorrectly wired (e.g. Connected as
2-wire instead of 3-wire system)
Zero point set wrongly
GB
Procedure
Replace instrument; if failure reoccurs,
consult the manufacturer *)
Replace instrument
Adjust the voltage supply to correspond
with the Operating Instructions *)
Check connections and cable
Follow pin assignment (see Instrument
Label / Operating Instructions)
Adjust zero point correctly (see chapter
8); a sufficiently accurate current/volt
meter should be used
17