Emerson 7003M - Manual (Page 41)

Operator Manual
748223-K
June 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Operation 3-15
Model 7003M
d. Zero Offset Adjustment
Following the last procedure, the current
zero offset value will be flashing.
NOTE
When flowing zero gas over the sen-
sor, ensure that there are no leaks and
the gas actually has zero oxygen con-
centration. Otherwise, significant er-
rors will result. Zero offset adjustment
is generally not required. Errors are
more often due to incorrect zero gas
oxygen concentration than residual
current of the oxygen sensor.
The zero offset adjustment allows the
operator to compensate for any residual
sensor current. Adjustment range is 0-5%
equivalent oxygen.
Sensor Current = Current from
Oxygen + Residual Current
NOTE
Adjusting the zero offset affects the
output of the Model 7003M. Therefore,
if the zero offset is changed, the sys-
tem must be re-calibrated with span
gas.
Zero Offset Is Not To Be Changed
Press ENTER to return analyzer to RUN
mode, and skip the remainder of this
procedure.
Zero Offset Is To Be Removed
1. Press the UP ARROW until the
maximum value is displayed.
2. Press ENTER and re-calibrate with
span gas per Section 4-2b on page 4-
1.
Zero Offset To Be Adjusted
1. Expose the sensor to 100% oxygen-
free nitrogen or other inert gas and
allow the sensor signal to stabilize (2-
5 hours depending on sample
conditions).
2. Use the DOWN ARROW to bring the
displayed value to zero (for maximum
offset).
3. Press ENTER to return to RUN mode.
4. Re-calibrate with span gas per
Section 4-2b on page 4-1.