Hach ORBISPHERE 366 Series Basic User Manual page 28

7. Press "CAL" again within a 3-second period.
8. The displays shows the measured current to ideal current percentage.
9. When the reading is stable, press "CAL" again.
10. Install sensor back in place.
7.3.7 Calibration procedure for hydrogen sensor
Hach Lange recommends the following calibration gas / inert gas combinations for calibrating with
the following membranes:
Membrane
2956A
2952A
2995A
29015A
The Windows ATEX 3660 software must be used for this procedure. To calibrate:
1. Switch on the instrument, if necessary, and wait approximately one minute for the displayed
measurement to settle.
2. Expose the sensor to a calibration gas sample with a known hydrogen concentration.
Note: Once you start introducing calibration gas via the flow chamber, some time is required for measurements
to stabilize. About 20 minutes is normal for membranes 2956A and 2995A; closer to an hour is usually required
for membrane 29015A. It depends on the cleanliness of the sensor and the variation in H
to calibration gas.
3. Enter the percentage of hydrogen in the calibration gas, using the ATEX 3660 software
"calibration Gas" menu.
4. Press the "CAL" key.
5. A brief clearing ("- - -") message appears.
6. Press "CAL" again within a 3 second period.
7. The percentage of the measured current to the ideal one is displayed.
8. When the reading is stable, press "CAL" again.
Section 8 Troubleshooting
The Troubleshooting menu includes a series of instrument operating tests, and enables the
barometric sensor and external pressure sensor (when applicable) calibrations.
If analyzer is behaving improperly, failing to calibrate, giving inappropriate measurement values, use
the Troubleshooting menu to verify that the instrument is configured correctly for the application, and
that is in good operating conditions. The instrument must be connected to PC and in measurement
mode to perform the tests.
8.1 Serial link test
Normally, the instrument will warn the operator of a disconnected RS-232 or RS-485 (serial) link.
Confirmation of a good connection can be done with the 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 instrument will display back the same text in the Echo box.
8.2 Keyboard test
Choose Keyboard Test from the Troubleshooting menu to check instrument keys. The following
dialog box is displayed to test the instrument keyboard. Press any keys on the instrument for a
second; the associated square on the dialog box should darken.
28 English
Recommended calibration gas
1% H / 99% N
2 2
5% H / 95% N
2 2
10% H / 90% N
2 2
100% H
2
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