Emerson Process Management OXYMITTER 4000 IM-106-340 - Manual (Page 65)

Instruction Manual
IM-106-340, Rev. 4.0
May 2006
4-3
Oxymitter 4000
SW2 Setting
The factory sets this switch as follows:
1. Position 1 is HART/LOCAL. This switch setting controls the configura-
tion of the Oxymitter 4000. The defaults cannot be changed via
HART/AMS or the LOI unless the switch is in the HART position. Placing
SW2, position 1 in the LOCAL position forces the O
2
range to the setting
of position 2. The position 1 switch must be in the LOCAL position or
changes in SW2, position 2 will have no effect.
2. Position 2 determines the O
2
range. This can be set to either 0 to 10%
O
2
or 0 to 25% O
2
. The factory setting is 0 to 10% O
2
. If necessary, the
O
2
range can be configured from 0 to 40% O
2
. To select values within
this range, set SW2, position 1 to HART and then enter the range via
HART/AMS or the LOI. Do not change SW2, position 1 to LOCAL
unless you want to operate in the range specified by SW2, position 2.
3. Position 3 determines the output at startup or at an alarm. The settings
are 3.5 mA or 21.6 mA. The factory setting is 3.5 mA. At startup, the
current at the analog output is 3.5 mA or 21.6 mA.
4. Position 4 can be used to set the heater for 115 or 220 VAC operation.
This switch is functional only when the software is set for manual
voltage selection (Auto Tune = No). Otherwise, the internal electronics
auto detect the input line voltage and sets the heater voltage
accordingly (Auto Tune = Yes).
Read O
2
Concentration
Once the cell is up to operating temperature, the O
2
percentage can be read:
1. To access TP5 and TP6 under the LOI module (Figure 4-2), power
down the Oxymitter 4000 and remove the LOI module. Attach alligator
leads from a multimeter across TP5 and TP6. Install the LOI module
and power up the Oxymitter 4000. Allow time for the cell to reach
operating temperature. The calibration and process gases can now be
monitored. When a calibration has been initiated, the value at TP5 and
TP6 is the % O
2
seen by the cell. Oxygen levels, as seen on the
multimeter, are:
8.0% O
2
= 8.0 VDC
0.4% O
2
= 0.4 VDC
2. HART/AMS.
3. Model 751. The loop-driven LCD display.
Typically, the probe's sensing cell, in direct contact with the process gases, is heated to
approximately 1357°F (736°C). The external temperature of the probe body may exceed
842°F (450°C). If operating conditions also contain high oxygen levels and combustible
gases, the Oxymitter 4000 may self-ignite.