Emerson Process Management IM-106-340 instruction manual Model 751. The loop-driven LCD display

Instruction Manual

IM-106-340, Rev. 4.0 May 2006

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 O2 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 O2 range. This can be set to either 0 to 10% O2 or 0 to 25% O2. The factory setting is 0 to 10% O2. If necessary, the O2 range can be configured from 0 to 40% O2. 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.

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.

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 O2 Concentration

Once the cell is up to operating temperature, the O2 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 % O2 seen by the cell. Oxygen levels, as seen on the multimeter, are:

8.0% O2 = 8.0 VDC

0.4% O2 = 0.4 VDC

2.HART/AMS.

3.Model 751. The loop-driven LCD display.

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