biosystems PhD Lite, Reference Manual

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and functioning normally, an animated “ ” icon will
appear in the upper left-hand corner of the LCD display.
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CAUTION:
Never perform remote sampling with
the PhD Lite without the sample probe assembly.
The sample probe handle contains replaceable
filters designed to block moisture and remove
particulate contaminants. If the pump is operated
without the probe assembly in place, particulate
contaminants may be drawn into the instrument
causing damage to the pump, sensors and internal
components of the PhD Lite.
The motorized sample pump includes a pressure sensor
designed to protect the PhD Lite from exposure to water
or other liquids. If there is a sufficient change in
pressure in the sample draw assembly due to fluid
intake or other blockage, the pump immediately shuts
down. After a few seconds audible and visible alarms
indicating a low flow condition will also be activated.
Pump Fault
Pump Low Flow
Remove Blockage
Pump Low Flow
MODE=Acknowledge
CAUTION:
Make sure that the sample draw tube
is not inserted into a fluid horizontally or at a low
angle.
The pressure sensor in the motorized pump is designed
to detect changes while the sample-draw probe is being
held in a vertical position. If the probe is held
horizontally or at a low angle while immersed in a fluid,
pressure sufficient to cause the pump to shut down may
not be generated, and water may be drawn into the
pump assembly causing damage to the pump, sensors
and internal components of the PhD Lite.
To avoid potential damage, care must be taken to keep
the probe vertical whenever fluids may be present.
As an additional safeguard, the pump contains an
internally-housed particulate filter. If the pump is
operated without the sample probe assembly in place,
or in a particularly dirty atmosphere, this internal filter
may become clogged and require replacement.
Standard accessories with every 54-26-0101 motorized
pump include a package of 10 replacement filters for the
pump (Biosystems part number 61-001).
6.2.1 Pump performance
The PhD Lite automatically verifies pump performance
upon start-up of the instrument, or whenever the pump
is attached during normal operation.
6.2.1.1 Verifying pump performance
Pump performance is automatically tested when the
pump is attached to the instrument. A similar test is
automatically initiated if the pump is attached prior to
turn-on.
1. Attach the pump to the PhD Lite. Make sure that
the sample probe and tubing assembly is attached
to the pump inlet.
Pump Detected
2. The PhD Lite will automatically prompt the user to
test the pump system.
Pump Testing
Block Sample
3. Verify that there are no leaks in the system by
covering the end of the sample probe tube with a
finger. If there are no leaks a message will be
displayed indicating that the pump test passed.
Pump Test Passed
Remove Blockage
4. Press the MODE button to reset the pump. The
following screen will then be displayed. Notice the
animated “
” icon in the upper left corner of the LCD
display, which indicates that the pump is attached
and in normal operation.
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6.2.1.2 Pump test failed
The pump includes a pressure sensor designed to
measure pump flow. If there is insufficient pump flow,
the pump test will fail and the PhD Lite will display the
following message.
Pump Test Failed
Remove Pump
Remove the pump. Since pump failure results from
insufficient pump flow, there is either a leak in the
sample draw system or the pump itself is not operating
properly.
To locate or rule out a leak in the sample draw system:
1. Remove the sample draw probe and tubing from
the pump.
2. Reattach the pump to the instrument without the
sample probe and tubing assembly. The
instrument will again proceed with the pump test.
3. Block the pump inlet with a finger. If the pump test
passes, then the leak is located in the probe and
tubing assembly. If the pump test fails, then the
failure is inside of the pump itself.