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3. Maintenance
3.1. General
The detector contains an automatic compensation function, which allows the detector to
operate correctly even when the amount of signal reaching the receiver has changed (the
compensation rate is
±
1%/20 minutes). This means that minor changes due to
contamination and beam alignment will not affect the sensitivity of the detector. There is
of course a limit that the detector can compensate for and this is -50% and +50% of the
initial setting. In order to maintain proper performance the detector should be checked
every six months.
3.2. Visual check
Check the condition of both the emitter and receiver for physical damage or any other
condition that might impair proper operation. Ensure that both the receiver and emitter
are still firmly secured to the wall or other fixing point.
If necessary clean the lens cover with a damp soft cloth. Washing liquid or detergent must
not be used.
3.3. Operation checks
Perform the sensitivity check function as defined in section 2.7.
3.4. Precautions for insulation resistance checking
If the wiring to a beam detector is to be tested for insulation resistance using a high
voltage tester such as a Megger, the wiring to the beam detector must be disconnected
from the detector otherwise permanent damage of the detector may result.
3.5. Re-initialisation after cleaning or re-adjustment
The detector incorporates non-volatile memory, where backup copies of the initial settings
and dirt progress are periodically made. This memory is retained even after the power is
turned off. Turning the power off and back on will cause the detector to reload the
settings which were in the memory before the power was turned off, then to shift to the
monitoring state.
To clean the cover, readjust the optical axis, or do something similar during maintenance
work, the memory must be cleared. The memory can be cleared in either of the following
two ways:
- Open the cover on the receiver while in a normal monitoring state.
- Turn on the power with the receiver cover open.
