Oil-on-Water
Monitor
|
- Model
ODL- 20 (Standard Model)
- Model
SODL-20 (Intrinsically Safe Model)
This
instrument is mounted above a water surface and detects
oil slicks providing immediate detection of oil-leakage.
The instrument projects a laser beam of visible light
onto the water surface and senses the difference between
reflections from water and oil films. This unit is a
new model successive to DKK's Models SODL-12, ODL-12
and OF-10 and features not only higher performance and
more ease-of-use but also lighter weight to facilitate
installation.
Features:
-
Non-contact
detection using a laser-beam.
-
Light
weight to facilitate easy installation.
-
Wide
installation distance of 0.3~2.0m above water surface
with no effect on performance for
water level variatiion within this range.
-
Microprocessor
based controller/transmitter.
-
Optical
filter system eliminates affects of sunlight on
performance.
-
Service
life of light source is 2 years.
-
Intrinsically
safe explosion protected version available.
|
|
|
Standard
Specifications
|
| Product
Name: |
Oil-on-water-Monitor |
| Models: |
ODL-20
(Standard Model), SODL-20 (Intrinsically Safe
Model)
|
| Measurement
Objective: |
Oil
slick on water surface.
|
| Measurement
Method: |
Reflectance
measurement of visible light.
|
| Installation
Distance: |
0.3-2m
(above water surface).
|
| Light
Source: |
Semi
conductor laser diode.
|
| Loop
Structure: |
Individual
detector and converter / transmitter. Max. allowable
distance between sensor and converter / transmitter
is 20m.
|
| Explosion
Protection: |
Intrinsically
safe system avaialble using zener barrier.
|
| Weather
Protection Standard: |
Weatherproof,
certified to JIS C 0920-1988 (IP-64)
|
| Ambient
Temperature: |
0~40
degrees Centigrade. |
| Sample
Water Temperature: |
Above
freezing point.
|
| Signal
Output: |
No
oil: 18 mA, oil slick detection: 20 mA.
|
| Power
Source: |
DC
24V +/- 1V
|
| Power
Consumption: |
Max.
0.6 VA |
| Weight: |
Converter
3.5 kg., Detector 7 kg. |
| Standard
Paint Finish: |
Blue
(Munsell 10 B5/10). |
| Cable
Port: |
G1/2
(with plug). |
| Other
Functions: |
Zero
span calibration function, Light source diagnostic
function, sensing condition adjusting function.
|
|
| |
Principle
of Operation
|
|
When
an oil slick is present on the water surface, it glitters
since the reflectance of visible light from an on film
is higher than that refected from water. Therefore,
the existence of an oil slick can be determined by sensing
the change in the intensity of reflected light from
the water surface when projecting a light beam of constant
intensity on to the water surface. The detector contains
a hanging a sensor unit consisting of a light source
(semi-conductor laser diode), a reflector (part-parabolic
mirror) and a reflected light sensor (photodiode). Its
optical axis has been factory- adjusted to the correct
alignment before shipment.
The laser beam emitted from the light source is reflected
from the water surface to the reflector, and it then
reaches the light sensort. A section of a parabolic
mirror is used as the reflector. Since the parabolic
reflection enables all of the light beams parallel to
its optical axis to come to the focal point after reflection,
the sensor placed at the focus point can mitigates differences
caused by of water level variations.
The converter a receives a signal from light sensor
and transduces it to an output signal to provide oil
detection signall. The output signal is normally DC18mA
and if oil film detected and is held at DC 20mA for
alarm signal. When a light sensing signal cannot be
obtained due to shut-off of the light source or due
to floating matter on the water surface, the instrument
generates a DC 16mA signal to signfy abnormal conditions.
|
| |
Display
Indication
|
The
converter has the following three kinds of display views:
|
|
RUN
|
Shows
normal water surface watching.
|
|
OIL
ALARM
|
Alerts
detection of the oil slick. It automatically
returns to the normal screen when no oil film
is on water surface any more.
|
|
ERR
ALARM
|
Notifies
that normal measurement cannot be implemented
due to shut-off of the light source or stagnation
of flotage on the water surface. Either case
requires to reset the alarm manually after checking
and removing the causes.
|
|
| |
Other
Functions
|
•
Zero span calibration
|
|
This
function takes light source shut-off as a zero signal
and oil film detection as a span signal for calibration.
For zero calibration, cover the lower edge of the detector
with a low-reflectance black.
|
| |
| •
Light source diagnostic function (Err Alarm) |
|
The
service life of the light source is approx. 2 years,
but it may vary depending on the working conditions.
If the light source lamp burns out prior to replacement,
light source shut-off will be determined, comparing
with the value of zero calibration.
|
| |
•
Oil Slick Detecting Condition setting
|
|
The
oil slick on water surface has a variety of forms, it
may be in a lump or scattered. The light sensing part
also senses different light signals, depending on the
water surface conditions such as wavy, calm. this oil-on-water
monitor allows optimum setting for such various conditions.
|
| |
•
Floating matter determination setting
|
|
This
function allows the setting of functions to recognize
low reflectance materials such as drifting wood on the
water surface.
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