50
8
SENSOR MAINTENANCE
8.1
Scheduled Maintenance
Warning.
DO NOT
open the emitter module. It
uses high voltages that can cause serious injury or
death.
Note.
The emitter and receiver modules contain no
user-serviceable parts and are sealed in clean and dry
conditions at the factory. Opening them will lead to
degraded performance. See also the
Warning
above.
The following maintenance schedule is a general guide only. The
systems are designed for a wide range of applications where the
nature of the sample can vary considerably, therefore it is
necessary to amend the schedule to suit the particular
installation and sample conditions.
8.2
Cleaning the Sensor
Routine maintenance is limited to cleaning out the flowcell
manually to remove accumulated fouling or sediment. The
flowcell
must
be cleaned prior to calibration (see Section 4) to
ensure that the Zero and Span standards are not contaminated
by organic matter that may be present inside.
8.2.1
Dismantling and Cleaning – Figs. 8.1 to 8.4
Warning.
Isolate the transmitter and sensor
from the power supply before dismantling the sensor.
UV
Warning.
The sensor emitter module
contains a high intensity xenon strobe lamp that emits
ultraviolet (UV) radiation.
This must NOT be viewed
with the naked eye and must NEVER be operated
while outside the sensor
. Under normal operating
conditions, it is not possible to see the light source but,
if the sensor is dismantled with electrical power applied,
it may be possible to expose the eyes to the strobe
flash.
Notes.
• The emitter and receiver modules contain precision
optical components and must be handled
accordingly.
• The emitter module contains the power supply,
voltage control and lamp components. As a result, it
is heavy and requires extra support.
• Do not support the modules by the cable(s) entering
their enclosures.
• Ensure that the O-rings are removed with the screw
collars securing the cleaner, emitter and receiver
modules; it is possible for these seals to be left inside
the flowcell.
