Det-Tronics SW9200x Slickwatch IR Oil Detection System - Manual (Page 5)

Threshold Detector: Instrument Status Alarm Relay
This threshold detector activates when the NUMERATOR
voltage level approaches zero. Activation of this thresh-
old detector causes the instrument status alarm relay to
de-energize. Because the relay is energized in normal
operation and is de-energized when the beam is
blocked or when an instrument malfunction occurs, the
alarm is fail-safe.
Receiver Power
The incoming power (115 VAC) is used to operate the fil-
terwheel motor, the oil alarm relay, the obstruction/instru-
ment status alarm relay and the low voltage power sup-
plies. The instrument’s signal circuits are powered by a
±15 VDC supply. The circuit that controls the photode-
tector’s thermo-electric cooler is powered by a +5 VDC
supply.
Fuses
The incoming power line is fused internally to protect the
instrument from damage. These fuses are accessible on
the front panel.
Section 2
Operation
SAFETY INFORMATION
EXPLOSION-PROOF INTEGRITY
WARNING
The SW9200 housings or associated junction
boxes must never be opened when circuits are
alive and hazardous vapor conditions may exist. In
procedures where the cover, window assembly or
junction box is to be opened when circuits are alive,
first ensure that no hazardous vapor conditions
exist.
CAUTION
If power is to be disconnected for an extended peri-
od, e.g., over one week, the instrument should be
removed to a protected environment.
Special precautions must be taken with the SW9200 to
ensure the integrity of the explosion-proof housings.
When the instrument is in operation, the window assem-
blies must be securely tightened. The cover bolts must
be torqued to 20 foot pounds.
It is recommended that the window retaining ring tight-
ness be verified after shipment and just prior to initial
setup. The window assembly retaining ring must be
tightened to hold the window securely against the win-
dow cover. The retaining ring must be tightened until
0.003-inch feeler stock will not penetrate more than 1/8th
of an inch between the window and the window cover.
This should be checked on both the transmitter and the
receiver around the entire circumference of the window
on both the inside and the outside.
Scratches may affect the strength of the instrument win-
dows, so care must be taken to avoid scratching them
during installation, operation, and servicing. Similarly,
the mating surfaces of the cover and the housing flange
should not be scratched and these surfaces should be
protected during servicing.
The light beam projected by the SW9200 transmitter
could cause combustible materials within its path to
ignite, or raise the temperature of an object within its
path above the self-ignition temperature of some gases.
Check the temperature code for the transmitter wattage
used (see instrument nameplate) and do not install the
instrument at any location where this dangerous condi-
tion could occur. Do not allow any object to intercept
the transmitter beam path to the water surface.
PERSONNEL SAFETY
The American Conference of Governmental Industrial
Hygienists (ACGIH) has roughly established Threshold
Limit Values (TLVs) or maximum allowable exposures to
bright light sources during an eight-hour workday.
According to ACGIH, “these values are to be used as
guides to the control of exposure to light and should not
be regarded as the fine line between safe and danger-
ous levels”.
WARNING
It is possible to exceed the ACGIH limit values by
viewing the oil slick detector’s light source directly
from the center of the light beam at distances less
than approximately ten feet from the source. DO
NOT stare directly into the light source at close
range.
As with the sun, which greatly exceeds the Threshold
Limit Values established by the ACGIH, the eye’s self-
protection mechanism (blinking) activates and automati-
cally prevents overexposure.
FRONT PANEL CONTROLS
Front panel controls are described in the following para-
graphs and are illustrated in Figure 2. Access to the front
panel controls is gained by removing the receiver win-
dow assembly.
ZERO
The ZERO adjustment potentiometer is used to factory
set the analog output (RATIO) for oil-free water.
4