Emerson Process Management IM-106-340 Defining a Timed Calibration VIA Hart Trim Procedure

Instruction Manual

IM-106-340, Rev. 4.0 May 2006

Oxymitter 4000

DEFINING A TIMED CALIBRATION VIA HART

D/A TRIM PROCEDURE

11.When the "Loop should be returned to automatic control" message appears, return the Hazardous Area Oxymitter 4000 to the automatic control loops previously removed and press OK.

12.At the STOP GAS status prompt, select menu item 2, NEXT CAL STEP When the status displays PURGING, select menu item 4, EXIT, to leave the O2 CAL procedure.

13.From the PERFORM O2 CAL screen, view menu item 3, CALSTATE, to monitor the calibration status as it updates. Or, access the O2 CALI- BRATE screen and select menu item 2, O2 CAL STATUS, to view menu item 1, CAL-STATE; menu item 2, TIMEREMAIN; and menu item 3, PRESENT O2, as the calibration status updates.

14.When CALSTATE displays COMPLETE, the calibration is finished.

Use the following procedure to specify a time interval (in hours) at which the Oxymitter 4000 will be automatically calibrated. If necessary, use the menu tree in Figure 7-3(Sheet 2 of 3) for reference.

NOTE

To select a menu item, either use the up and down arrow keys to scroll to the menu item and press the right arrow key or use the number keypad to select the menu item number. To return to a preceding menu, press the left arrow key.

1.From the DEVICE SETUP screen, select DETAILED SETUP.

2.From the DETAILED SETUP screen, select O2 CALIBRATION.

3.From the O2 CALIBRATION screen, select menu item 6, CAL MODE. Set the CAL MODE to AUTO.

4.Return to the O2 CALIBRATION screen and select menu item 7, CAL INTRVL.

5.At the prompt, input a time interval (in hours) at which an automatic calibration will occur; then press ENTER.

The D/A trim procedure is used to calibrate the 4-20 mA output signal to a precision mA measurement device (calibrated digital ammeter, etc.). The procedure is interactive and stored in the Oxymitter software.

Use one of the following communication methods to access the D/A trim procedure:

LOI Menu

1.Use the "Z" pattern key entry to access the LOI menu.

2.Press the down key two times to access the SYSTEM menu.

3.Press the down key once to access the Input/Output menu.

4.From the Analog selection, press the right-pointing key to display the Analog submenu listing.

5.Press the down key as needed to access Trim O2 Out.

6.Press the Enter key to start the trim procedure. Follow the LOI display prompts to perform the trim procedure.

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