User's Manual

9
Calibration Steps
Use the following step-by-step procedure to perform ZERO and SPAN calibrations.
1. To enter the CAL MODE activate the DOWN / CAL key with the magnet and within 5
seconds activate the EDIT key.
2. Using the Cal-Cup, apply clean ZERO gas (air) from canister or be sure there is no
background target gas in the monitored area if ambient air is used. After the reading is
stable, (approximately 1 minute) activate the EDIT key to perform a ZERO calibration.
3. If the ZERO calibration is successful, activate the NEXT key to proceed to the SPAN
check.
4. Apply the correct SPAN gas at 0.5 liters/min. After the reading is stable, (approximately
1 minute) activate the EDIT key to perform a SPAN calibration.
WARNING: The SPAN gas used must match the value specified since this is what the
ECO-A-X will indicate after a successful SPAN calibration. The Cal Span Value may be edited if
it becomes necessary to apply a different gas concentration (see Set Span Value at top of flow
chart below).
5. If the SPAN calibration is successful, the display flashes “REMOVE CAL GAS” and starts
the CAL PURGE delay.
6. CAL MODE will be complete after the end of the CAL PURGE delay.
The flow chart in Figure 4-2 illustrates the above procedure. UP, CAL, NEXT & EDIT labels
indicate keystrokes using the magnet. The CAL MODE information screen (top of the chart) is
available for advanced users to see Offset / Gain calibration constants and live analog to digital
converter (A/D) counts. Span Gas calibration values may also be edited from this screen.
Holding the UP key, for 5 seconds during CAL MODE, displays this screen.
Calibration history records are logged and may be viewed in the Sensor Information menu (see
section 5-5).