ENMET OMNI-4000 - Manual (Page 53)

OMNI-4000 S/N 6705 and above ENMET Corporation
47
Inputting the Calibration Value
• This procedure defines the content of the calibration gas which will be applied into the toxic sensor. The
maximum permissible content is the maximum value of the sensor range. The display shows a message such as:
To modify this value:
• Move to the digit to change in the number by repeatedly pressing the BACKLIGHT switch.
• Display the desired number by repeatedly pressing the MENU switch.
• Continue as above until the desired number (calibration gas value) has been obtained, then press the ENTER
switch. The value of the calibration gas to be used is memorized.
Calibrating Zero
This operation must be carried out in an environment which is free of gas contamination.
The display shows, for example:
• Press ENTER. The value is automatically reset to zero by the OMNI-4000.
Calibrating the Sensitivity
The display shows the offset value as memorized when the zero was set. Do not press a switch.
• Apply the calibration gas. You must be able to just hear the gas. The flow rate must be approximately 1 l/min.
Warning: This operation is performed using a toxic gas!
• When the reading has stabilized, press ENTER. The display shows:
• Press:
• ENTER to confirm the data entry and allow the return to the initial "Calibrate a Sensor" menu. It is now possible
to calibrate another channel by pressing ENTER. It should be noted that the channel number has automatically
been incremented. If there are no further channels to calibrate, go to the "Return to the Operator Mode"
paragraph.
• Pressing any other switch results in return to the initial "Calibrate a sensor" menu without memorizing the value
entered during the above calibration procedure.
Problems
As soon as ENTER has been pressed after the sensitivity calibration, the display may show:
• "Excessive zero offset": Check the local atmosphere (gas or cigarette smoke present during calibration of a CO
channel) and recalibrate. If the fault persists, change the sensor.
• "Scale Exceeded": A discrepancy exists between the content of the calibration gas and that set in the "Inputting
the Calibration Gas Value" procedure. Perform the calibration procedure again. If the fault persists, change the
sensor.
• "Sensor used": A possible discrepancy exists between the applied calibration gas value and that set during the
"Inputting the Calibration Gas Value" operation, or the calibration was attempted but gas was not used. Perform
the calibration procedure again. If the fault persists, change the sensor.
Cal gas:
0300 ppm CO
Zero
005 ppm CO
Span Value
005 ppm CO
Accept: ENTER
Cancel: ¨