Hach ORBISPHERE 3650 ATEX Manuel D'utilisation De Base page 21

6. When the reading is adjusted to the known concentration, press CAL again.
7. The instrument displays CAL and returns to the measurement mode.
8.3.3 Calibration in air (oxygen sensors only)
The oxygen sensor can be accurately calibrated in air. To perform this type of calibration, the
instrument must be set for calibration In air.
In order to calibrate the sensor in air, you will need to extract it from its mounting or flow chamber,
and wipe dry the sensor protection grille (if applicable).
Calibration is best achieved using the storage cap that protected the sensor during shipment. Put
several drops of tap water in the cap, shake out the excess, and then attach it to the sensor by
means of its collar. It is best to leave the cap slightly loose, to avoid compressing the air inside. The
cap and sensor should be about the same temperature.
Switch on the instrument, if necessary, and wait a minute or so for the displayed measurement to
settle.
1. Press the CAL button. Remember, this button may have been locked out to prevent an accidental
reset (see Locking out the instrument's CAL button
2. A brief clearing [- - -] message appears.
3. Press CAL again within a 3 second period.
4. The percentage of the measured current to the ideal one is displayed.
5. When the reading is stable, press CAL again.
If the new calibration current is within 25% to 175% of the ideal current, the instrument displays
CAL and returns to the measurement mode. Calibration is now complete, the sensor is
calibrated, and you can proceed with your measurements. If the new calibration current is not
within this range, the instrument displays Err and returns to measurement mode. The system will
not calibrate, and it is likely that a sensor service will be required.
Section 9 Maintenance
9.1 Instrument
If there are problems with the instrument, please contact your local Hach Lange service
representative.
9.2 Sensor
For information on sensor maintenance and servicing, please refer to the accompanying Sensor
Manual.
Section 10 Troubleshooting
If your analyzer is behaving strangely (failing to calibrate, giving inappropriate measurement values,
etc.) and you have attempted to rectify the problem by servicing the sensor, but to no avail, you may
wish to use the Troubleshooting menu of the PC WinLog97 program to make sure that the
instrument is configured correctly for your application, and is in good working order.
The instrument must be connected to your PC and placed in measurement mode to perform these
tests.
10.1 Serial test
Normally, the analyzer will inform you of a disconnected RS-232 (serial) link when appropriate.
However, you can confirm a good connection using the Troubleshooting, Serial Link Test by
echoing a test message via the instrument.
Enter text characters in the Text to be sent box, then click Send. If the serial link is operating
correctly, the exact same text will be displayed back from the instrument in the Echo box. Choose
Cancel to exit from this test box.
on page 18 for details).
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