Zero Transducer - ABB XSeriesG4 User Manual

6.17 Zero Transducer

During the process of setting pressure markers to determine the need for a calibration of either the static pressure (SP) or the
differential pressure (DP), it may be concluded that the SP or the DP pressures are out of alignment exactly the same amount at
each pressure marker (linear shift). When this occurs, the flow computer may need to be recalibrated, or the transducer may
need to be zeroed. The preferred method is to recalibrate the XIMV. This maintains the records in a manner that is assures
accountability and continuity when other measurement issues arise. By using the Zero Transducer command, all references to
previous pressure markers are non-existent, eliminating the ability to adjust volumes based on previous markers.
NOTICE – Tained results. Using the zero transducer capability assumes that the shift is Linear, meaning that at
different levels of pressure that the XIMV is off by exactly the same amount. If this is not the case, you need to
recalibrate the XIMV instead.
6.17.1 Static Pressure
The SP can be zeroed without recalibrating. If the SP shifts, the user can enter a new barometric pressure value. This shifts the
SP XIMV curve.
To zero the Static Pressure (SP):
1. Connect the PC running PCCU32 to the flow computer with either an MMI cable (RS-232), a USB cable or an Ethernet
cable.
2. Open PCCU.
3. Select the Calibration button from the toolbar.
4. Select the appropriate device in the tree.
5. Select the Static Pressure tab.
4. Select the Zero Transducer button.
The SP is now zeroed.
6.17.2 Differential Pressure
The DP can be zeroed without recalibrating. If DP shifts, the user can enter a new zero (0). This shifts the DP curve.
To zero the Differential Pressure (DP):
1. Connect the PC running PCCU32 to the flow computer with either an MMI cable (RS-232), a USB cable or an Ethernet
cable.
2. Open PCCU.
3. Select the Calibration button from the toolbar.
4. Select the appropriate device in the tree.
5. Select the Diff. Pressure tab.
4. Select the Zero Transducer button.
The DP is now zeroed.
137 XFC G4 2103335 Rev AB