3654 Portable H2/N2 Analyzer - Maintenance and Troubleshooting 43 of 66
Operator Manual ORBISPHERE
6.1 Power Supply
It is important to maintain power to the instrument at all times, (either batteries or an
external power supply) to ensure the sensor is continually purged and so prevent
damage to the TC sensor chip.
If the 3654 instrument is operating on battery power (two standard C-type cells), and the
battery power should drop, a [LO BAT] warning message is displayed in the instrument
LCD's top left corner.
To install the batteries, unscrew the battery cap (on the right side of the instrument) with
the tool provided in the recharge kit, or with a coin or flat bladed screwdriver. Place the
cells lengthwise into the battery compartment (positive end first), and then replace the
cap. Refer to the diagram on the back of the instrument.
Rechargeable nickel-cadmium batteries may be used. Expect about 15 hours of
autonomy in continuous operational use, or 3 weeks in standby (with purge gas
supplied). Alkaline batteries provide the longest continuous use though mercury-free
batteries are available that present less of a disposal problem.
Make sure that a fully charged (or fresh) set of batteries is installed before switching on
the instrument.
6.2 Sensor Maintenance
6.2.1 Maintenance Schedule
Sensor maintenance includes membrane replacement and external cleaning to restore
the original sensor sensitivity. This means low running costs and down time reduced to
a minimum.
The membrane needs to be replaced once or twice a year depending on application
conditions. This can be tailored accordingly.
Note:
If you are not familiar with Orbisphere sensor servicing, your Hach Ultra representative
will be glad to assist you
6.2.2 Testing the Sensor Condition
Periodically, visually inspect the sensor head for any deposits. Rinse it under clean tap
water, and dry with a clean tissue.
To verify the sensor, check measurements vs. a known standard sample value:
• If reading deviation is ±1% of the expected value, no action needs to be taken.
• If deviation exceeds ± 1%, perform a new calibration.
• If deviation exceeds 10% of the original values, replace the membrane.
CAUTION:
Carry out the maintenance in a clean dry place in order to avoid damaging the sensor's
precision components, and also to prevent water or humidity from getting into the
sensor.