Calibration Procedure for
O2 sensor
Use clean ambient air as calibration gas otherwise, use certified instrument air.
Be sure the
Ensure that the sensor is in a clean air environment before beginning the calibration procedure.
To enter the main menu, activate the magnetic reed switch or manual push button switch. When the countdown from 5 to 0 is complete remove the magnet from the magnetic reed switch or release the CAL/RESET push button. When prompted with Calibrate sensor “YES?” select the function by momentarily placing the magnet on the reed switch or depressing the CAL/RESET button. The selection is acknowledged with flashing “YES”. The controller starts calibration. The following Instructions are scrolled across the display for calibration:
Apply Calibration Gas - at this time the input should be ambient air (3.0mA output current level).
Processing - The sensor is reading the ambient air level (3.0mA output current level).
20.9- The sensor is calculating the corrected oxygen level (3.6mA output current level).
Remove Calibration Air - at this time input should be reduced to 3.6 mA by removing span gas from the sensor if it is attached (3.6mA output current level).
Calibration Complete - Returns to normal operation (17.38 mA output current)
NOTE:
If span setting does not complete successfully within ten minutes of starting the calibration sequence the status LED alternates flashes of RED and GREEN, the analog output changes back and forth from 3.0 to 3.3mA and Fail Cal. message is displayed on the screen. The unit remains in this state until acknowledged by a manual Reset. After manual Reset the program will return to the normal operation mode using previous calibration values. Since the calibration was unsuccessful another attempt may be made or replace the sensor and
Relay Settings
This option allows the user to set the alarm levels, coil status and the latch status of the low and high alarm relays. Fault alarm is fixed as normally Energized and
Enter the main menu and activate the magnetic reed switch/CAL/RESET button when prompted for
“Set Relay Options” with YES?. The selection is acknowledged with a fashing “YES”. The output current will drop to 3.0mA and the
Step 1. The low alarm level is set first. “Set Low” is scrolled across the screen followed by the alarm level setting which increases by increments of 5 (.5 % for the ST1400 O2 sensor) every 2 seconds. Actuate the
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