18
(6) Correlation between thickness of detected oil layer and cable load
The weight of cable is 100g/m. Floater is so adjusted as to detect a 4mm thick layer of
kerosine under a load of 1 m long cable.
Detected oil layer thickness is in proportion to the sinking depth of electrodes.
Accordingly, with increased load of cable given on floater, the detected oil layer depty
increases.
In case floater swings sideways, these swings likewise influence the oil layer depty at
which the presence of oil is detected.
Therefore, where water waves regularly cause large lateral swings of floater; some
appropriate measure to offset such influence has to be taken.
As such measure, the following two" " methods are conceivable:
1) To make smaller the head of inflowing wastewater or to scatter the in-flowing course of
the water.
2) To make smaller the waves at the location of detector by placing their wave-breaking
plate, net, chamber, etc.
(7) Noise proof structure
A high frequency (around 1 MHz) is used inside this detector, which, therefore, may issue
false signal if a transceiver or other high frequency source is nearby.
Though this new Apolarm (CSR-3005E) has enhanced its immunity against external
interference, do not use, as much as possible, such a transceiver, etc. near the Apolarm.
If it is not allowed to keep a sufficient distance from the noise source, design the
installation rack and cables of the Apolarm-C into a shielded structure.
