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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

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