Emerson manual Verify Oxymitter 4000 Configuration, SW2, Model 751. The loop-driven LCD display

Instruction Manual

IB-106-340 Rev. 3.0 December 2003

Oxymitter 4000

c.Verify Oxymitter 4000 Configuration

Located on the microprocessor board, the top board, are two switches that configure outputs (Figure 3-2). SW1 determines if the 4-20 mA signal is internally or externally powered. SW2 determines:

1.Range control, HART or LOCAL.

2.Oxygen range, 0 to 10% O2 or 0 to 25% O2. (0 to 40% O2 is also configur- able only through HART/AMS.)

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 position 1 of SW2 to HART and then enter the range via HART/AMS. Do not change position 1 of SW2 to LOCAL unless you want to operate in the range specified by position 2 of SW2.

3.The 4-20 mA signal, at fault or power up, 3.5 mA or 21.6 mA.

Remove power before changing de- faults. If defaults are changed under power, damage to the electronics package may occur.

d.SW1

The two settings are internally or externally powering the 4-20 mA signal. The factory setting is for the 4-20 mA signal to be inter- nally powered.

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 se- lection (Auto Tune = No). Otherwise, the internal electronics auto detect the input line voltage and sets the heater voltage accordingly (Auto Tune = Yes).

f.Once the cell is up to operating temperature, the O2 percentage can be read:

e.SW2

The factory sets this switch as follows:

1.Position 1 is HART/LOCAL. This switch controls the configuration of the Oxy- mitter 4000. The defaults cannot be changed via HART/AMS unless the switch is in the HART position. Placing this switch in the LOCAL position forces the O2 range to the setting of position 2. This switch must be placed in the LOCAL position or changes in position 2 will have no effect.

Typically, the probe’s sensing cell, which is in direct contact with the pro- cess gases, is heated to approximately 1357°F (736°C), and the external tem- perature of the probe body may ex- ceed 842°F (450°C). If operating conditions also contain high oxygen levels and combustible gases, the Oxymitter 4000 may self-ignite.

1.Access TP5 and TP6 next to the mem- brane keypad. Attach a multimeter across TP5 and TP6. The calibration and process gases can now be moni- tored. Pressing the INC or DEC once will cause the output to switch from the process gas to the calibration gas. Pressing INC or DEC a second time will increase or decrease the calibra- tion gas parameter. If the keys have been inactive for one minute, the out- put reverts to the process gas. 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.

3-2 Configuration with Keypad Rosemount Analytical Inc. A Division of Emerson Process Management