Correcting The Lower Range Value / Zero Shift - ABB 265GS Operating Instruction

Commissioning
6.3

Correcting the lower range value / zero shift

During installation of the transmitter, zero position shifts caused by the mounting position (e.g.,
a slightly oblique mounting position due to a remote seal, etc.) may occur; these must be
corrected.
IMPORTANT (NOTE)
The transmitter must have reached its operating temperature (approx. 5 min. after startup, if
the transmitter has already reached the ambient temperature) in order to perform zero position
shift correction. The correction must be made at p
p
abs
There are two options (point A or B) for correcting the 4 ... 20 mA output signal directly on the
pressure transmitter:
IMPORTANT (NOTE)
The button unit must be available for this purpose. Operating the buttons using a magnetic
screwdriver is not permitted.
A. Set lower range limit value
1. Apply lower range limit value pressure (4 mA) from the process or from a pressure
generator. The pressure must be stable and applied with a high level of accuracy << 0.05 %
(observing the set damping value).
2. Press the "0 %" button on the pressure transmitter. The output signal is set to 4 mA. The
span remains unchanged.
IMPORTANT (NOTE)
A lower range limit value set using this method will be stored in the non-volatile memory < 25 s
(HART), < 110 s (PROFIBUS PA), and < 15 s (FOUNDATION Fieldbus) when the
"0 %" button is pressed for the final time.
B. Correct the zero shift
1. Use the LCD display (installed as an option) to call up the "SHIFTZERO" menu item using
the pushbuttons "M" and "+".
2. The correction is made by pressing the "M" button (refer to the section "Configuration with
the LCD display").
3. Put the pressure transmitter into operation as described at the beginning of this section.
IMPORTANT (NOTE)
The procedure described in "A" above does not affect the physical pressure shown; it only
corrects the analog output signal. For this reason, the analog output signal may differ from the
physical pressure shown on the digital display or the communication tool.
To avoid this discrepancy, correct the zero position shift (zero shift) via the graphical user
interface (DTM).
Menu path: „Configure Pressure Measurement_Process Variable"
However, the lower range limit value must not have been corrected already using the "0 %"
button.
40
= absolute 0.
= 0 or, for absolute pressure equipment, at
e
265Gx, 265Ax IM/265Gx/Ax-EN-07