Section 5 Maintenance; Preventive Maintenance; Cleaning The Instrument - Hach FLO-DAR User Manual

Section 5 Maintenance
Danger
Explosion hazard. When using the retrieval pole, make sure to connect the
grounding strap to the ground lug of the barrier with the sensor cable (at least the
shields) terminated to the barrier. This is to prevent ignition of explosive gases due
to static discharge.
The safety of the transmitter may be impaired if any of the following conditions
have occurred:
If any of these conditions have occurred, return the device to the manufacturer for
recertification.
CAUTION: Radar RF Exposure Hazard
Although the Flo-Dar microwave power level is very small (~15mW) and is well
below government stated exposure limits for uncontrolled environments, users of
this product should follow proper safety protocols for the handling of devices with
radar frequency transmitters. Avoid placing the head and other vital organ areas
within the microwave beam (within 1 meter of the microwave aperture).
Important Note: Delicate Instrumentation. Handle with care to prevent damage to the
microwave transmitter. Damaged transmitters can result in higher signal power levels,
which can interfere with essential terrestrial microwave links.

5.1 Preventive maintenance

Examine the Flo-Dar sensor on an annual basis to look for corrosion or damage that can
allow environmental gases into the interior. Make sure that no swelling, blistering, pitting
or loss of material has occurred on the upper and lower portions of the main plastic
enclosure, the depth module or the radome.
If the extended depth sensor is used, examine the enclosure and the four ¼-20 SS bolts.
If the surcharge velocity sensor (SVS) is used, make sure the unit is not corroded and the
labels are readable. Inspect the cable connectors for any damage or corrosion and
tighten all connectors in the system.
The only parts of the Flo-Dar system that can be replaced by the user are the bail
assembly, cable and desiccant. If the sensor becomes defective, it must be replaced as a
complete unit.
Check the electrical connections
Examine the cable connectors on an annual basis for corrosion and tightness. If
corrosion is found, clean and dry the connectors to make sure that no moisture is on the
connector pins. If corrosion is severe, replace the cables.

5.2 Cleaning the instrument

Regular cleaning is not necessary because the sensor does not contact the flow unless a
surcharge condition occurs. Examine the sensor after a surcharge to see if cleaning is
necessary.
Prerequisites
• visible damage
• storage above 70ºC for prolonged periods
• exposure to severe transport stresses
• previous installation
• failure to operate properly
• Retrieval pole with hook (optional, see Accessories on page 33)
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