Emerson World Class 3000 Bedienerhandbuch Seite 51

  • Herunterladen
  • Zu meinen Handbüchern hinzufügen
  • Drucken
  • Seite
    / 158
  • Inhaltsverzeichnis
  • LESEZEICHEN
  • Bewertet. / 5. Basierend auf Kundenbewertungen
Seitenansicht 50
Instruction Manual
106-300NFX Rev. 4.2
January 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Setup and Operation 3-9
World Class 3000
Table 3-6. Efficiency Constants
CONSTANT
UNITED
STATES
GAS OIL
EUROPE
GAS OIL
K1 0.407 0.432 0.66 0.69
K2 0.0 0.0 0.0082 0.0051
K3 5.12 5.12 12.28 8.74
3-10 SYSTEM CALIBRATION
a. Overview
The primary purpose of an oxygen analyzer
is to give an accurate representation of the
percentage of O
2
in the gas stream. The
system should be calibrated periodically to
maintain an accuracy which may otherwise
reduce over time due to cell aging.
A requirement for calibration is a set of two
accurate test gases spanning the oxygen
range of most interest. For example, 0.4%
and 8% for a 0-10% oxygen range.
Under normal conditions the probe should
not need frequent calibration. Because cali-
bration is necessary, the system can be
equipped with the optional MPS 3000 Multi-
probe Test Gas Sequencer for fully auto-
matic calibration at regular intervals.
Without an MPS, the probes must be cali-
brated manually (semi-automatically).
b. Probe Calibration
1. Previous Calibration Constants Func-
tionality. Three sets of registers are
used to store calibration constants.
These are: Latest Calibration, Previous
Calibration, and Calculation. Only the
values in the Calculation registers are
used to calculate the oxygen value for
display and representation on the
analog output signal. These values
may be changed in two ways:
(a) The operator may change the Cal-
culation values by entering the
SETUP menu and then entering
the O
2
Calculations sub-menu. The
operator may adjust the slope and
constant individually or reset both
to the values calculated during the
last good calibration. Simultane-
ously resetting both values is done
by selecting Load Constants and
pressing ENTER.
(b) The IFT will automatically change
the values after each successful
calibration.
The values in the Latest Calibration
registers are updated after every
complete calibration even if the cali-
bration is not successful. If the calibra-
tion is successful, the values in the
Latest Calibration registers are copied
into the Previous Calibration registers.
This function is accomplished prior to
the update of the Latest Calibration
registers. The values from successful
calibrations are automatically loaded
into the Calculation registers for use in
future O
2
calculations. If a calibration
fails, the Previous Calibration registers
and Calculation registers retain their
existing values, while the Latest Cali-
bration registers record the values of
the failed calibration.
2. Calibration Methods. There are three
calibration methods: manual (semi-
automatic), manually initiated auto-
matic, and fully automatic. Manual
(semiautomatic) calibration is done
without an MPS unit. Test gases are
switched on and off by the operator
and the IFT is sequenced through the
calibration procedure by the operator
with the front panel keyboard. The IFT
prompts the operator for the correct
action. Manually initiated automatic
calibration is done with an MPS. The
operator manually initiates the calibra-
tion at the IFT or through a remote
switch, and the IFT controls the opera-
tion of the MPS unit and the calibration
sequencing. Fully automatic calibration
requires no action from the operator.
The setup is the same as semiauto-
matic except the IFT automatically
3
Seitenansicht 50
1 2 ... 46 47 48 49 50 51 52 53 54 55 56 ... 157 158

Kommentare zu diesen Handbüchern

Keine Kommentare