Title of Invention

A FUEL CONTAMINANT SENSOR AND A DEVICE FOR DETECTING A CHANGE IN THE CONTENTS OF A FUEL-WATER SEPARATOR

Abstract The invention relates to a fuel contaminant sensor comprising a fluid reservoir (16) for containing a first fluid and a second fluid, the fluid reservoir having an inlet (18) and an outlet (20); a light source (36) for projecting a light beam through the fluid reservoir (16); a light beam detector (38) for receiving the light beam projected through the fluid reservoir (16); and a controller (34) for activating the light source (36) and receiving an output of the light beam detector (38); the first fluid and the second fluid define an interface (46) between the first fluid and the second fluid, wherein the interface (46) is disposed between the light source (36) and the light beam detector (38), and the second fluid has an index of refraction different than an index of refraction of the first fluid; and in that an interruption of the light beam due to a change of index of refraction between the first fluid and the second fluid at the interface (46) inhibits the light beam detector (38) from receiving the light beam (36).
Full Text

FIELD The present disclosure relates to contaminant sensing, and
more particularly to a fuel contaminant light sensor.
BACKGROUND
The statements in this section merely provide background
information related to the present disclosure and may or may not constitute prior
art.
Diesel engine fuel systems are sensitive to the presence of
water and other contaminants in the diesel fuel. Since water does not provide
the lubricity required for the tight fitting components of the diesel engine fuel
system, the presence of water in the diesel fuel can cause wear on the
components. In addition, water often contains biological and chemical corrosives
that can cause degradation of the diesel fuel system components. As such,
many diesel fuel systems use fuel-water separators to remove water and other
contaminants from the diesel fuel.
Fuel-water separators are typically coupled to a fuel line
between the source of the diesel fuel and the engine. Fuel-water separators
typically include a reservoir that collects the water and other contaminants after
they have been separated from the diesel fuel. While these fuel-water
separators work well for their intended purpose, the reservoir needs to be

interrogated to determine if the volume of captured water is such that it needs to
be drained and serviced. One form of interrogation known in the art is periodic
visual inspection through the optically clear reservoir of the fuel-water separator.
In recent years, electrically based sensors using electrodes
have been added to the fuel-water separators to trigger a warning signal
indicating that the reservoir needs to be drained. An electric potential is
impressed upon these electrodes which is not conducted through the electrically
non-conductive diesel fuel. However, when electrically conductive water is
present, the electric potential is conducted through the water, thereby indicating
the reservoir needs draining. While these electric sensors have worked well in
the past, the electrodes of the electric sensors are possibly subject to some of
the corrosive elements within the diesel and fuel contaminants. Therefore, there
is room in the art for an improved non-conductive water sensing system.
SUMMARY
In one aspect of the present invention a fuel contaminant light
sensor is provided.
In another aspect of the present invention the light sensor
includes a fluid reservoir having an inlet and an outlet, a light source for
projecting a light beam through the fluid reservoir, a light beam detector for
receiving the light beam projected through the fluid reservoir, and a controller for
activating the light source and receiving an output of the light beam detector. An

interruption of the light beam inhibits the light beam detector from receiving the
light beam.
In still another aspect of the present invention the interruption is
due to a change of an index of refraction of a fluid between the light source and
the receiver.
In still another aspect of the present invention the interruption is
due to a change of index of refraction due to the introduction of a second fluid
within the reservoir between the light source and the receiver.
In still another aspect of the present invention the second fluid
has an index of refraction different than an index of refraction of the first fluid.
In still another aspect of the present invention the first fluid and
the second fluid define an interface between the first fluid and the second fluid.
In still another aspect of the present invention the light beam is
refracted when the interface is disposed above the receiver and below the light
source.
In still another aspect of the present invention the interruption is
due to droplets of a second fluid passing across the path of the light beam.
In still another aspect of the present invention the light source is
positioned near a top of the reservoir and the detector is positioned near a
bottom of the reservoir.
In still another aspect of the present invention the light source
pulses the light beam.

In still another aspect of the present invention the light source
continuously emits the light beam.
In still another aspect of the present invention the light source is
a laser.
In still another aspect of the present invention the light source is
a light emitting diode.
In a second aspect of the present invention a device for
detecting a change in the contents of a fuel-water separator is provided.
In another aspect of the present invention the device includes a
fluid reservoir for containing a fluid, an emitter/detector coupled to the reservoir
for emitting a light beam through the fluid and for detecting the light beam, a
controller in electronic communication with the emitter/detector. The controller is
operable to activate the emitter/detector to emit the light beam and operable to
determine whether the light beam has been detected. A reflector is coupled to
the reservoir. The reflector is in alignment with the emitter/detector such that the
light beam emitted from the emitter is reflected by the reflector back to the
emitter/detector. An interruption of the light beam between the emitter/detector
and the reflector prevents the emitter/detector from detecting the light beam.
In still another aspect of the present invention, the interruption is
due to a change of index of refraction due to the introduction of a second fluid
within the reservoir between the emitter/detector and the reflector.
In still another aspect of the present invention the second fluid
has an index of refraction different than an index of refraction of the first fluid.

In still another aspect of the present invention the first fluid and
the second fluid define an interface therebetween.
In still another aspect of the present invention the interface
refracts the light when the interface is disposed above the reflector and below the
emitter/detector.
In still another aspect of the present invention the interruption is
due to a change of index of refraction in the fluid.
In still another aspect of the present invention the interruption is
due to droplets of a second fluid passing across the path of the light beam.
In still another aspect of the present invention the
emitter/detector pulses the light beam.
In still another aspect of the present invention the
emitter/detector continuously emits the light beam.
In still another aspect of the present invention the
emitter/detector includes a laser.
In still another aspect of the present invention the
emitter/detector includes a light emitting diode.
Further areas of applicability will become apparent from the
description provided herein. It should be understood that the description and
specific examples are intended for purposes of illustration only and are not
intended to limit the scope of the present disclosure.

ACCOMPANYING DRAWINGS
The drawings described herein are for illustration purposes only
and are not intended to limit the scope of the present disclosure in any way.
FIG. 1A is a schematic view of a fuel-water separator having a
first embodiment of a water sensing system according to the principles of the
present invention;
FIG. 1B is a schematic view of a fuel-water separator having the
first embodiment of the water sensing system of the present invention with water
present in the fuel-water separator;
FIG. 2A is a schematic view of a fuel-water separator having a
second embodiment of the water sensing system according to the principles of
the present invention; and
FIG. 2B is a schematic view of a fuel-water separator having the
second embodiment of the water sensing system of the present invention with
water present in the fuel-water separator.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is
not intended to limit the present disclosure, application, or uses.
FIG. 1A illustrates a sensing system 10 according to the
principles of the present invention. The sensing system 10 is illustrated in
operation with an exemplary fuel-water separator 12. However, it should be

appreciated that the sensing system 10 may be employed with any structure
having a reservoir for containing a substance, such as a. fuel tank or storage
container. The fuel-water separator 12 is typically located between a fuel supply
(not shown) and an engine (not shown) of a motor vehicle (not shown). The fuel-
water separator 12 is operable to separate water and other contaminates from
fuel, as will be described in further detail below. The fuel-water separator 12
generally includes a ported housing 14 and a cup-shaped reservoir 16. The
housing 14 includes an inlet port 18 for receiving a fuel from the fuel supply (not
shown) and an outlet port 20 for discharging the fuel once water and
contaminates have been removed. The housing 14 further includes a fuel
discharge port 22 and a fuel return port 24 located on a bottom surface 26 of the
housing 14. The reservoir 16 is sealingly secured to the bottom surface 26 such
that the fuel discharge port 22 and fuel return port 24 are located within a cavity
28 defined by the reservoir 16 and the housing 14.
During operation of the fuel-water separator 12, fuel from the
fuel supply (not shown) enters the housing 14 via the inlet port 18. The fuel
passes through a flow passage (not shown) within the housing 14 and is
discharged into the reservoir 16 via the fuel discharge port 22, as indicated by
the downward arrow. Water and contaminants, which are heavier than the fuel,
settle to a quiet zone 30 located at the bottom of the reservoir 16. The fuel then
returns to the housing 14 via the fuel return port 24, as indicated by the upward
arrow. The fuel may then be further filtered within the housing 14 before being
discharged from the fuel-water separator 12 via the outlet port 20. To remove

water or contaminants from the quiet zone 30, the fuel-water separator 12
includes a drain valve 32 located at the bottom of the reservoir 16. The drain
valve 32 communicates between the reservoir and the surrounding environment.
Opening the drain valve 32 allows the contents of the reservoir 16 to be
discharged therefrom.
The sensing system 10 includes a controller 34 in electronic
communication with an emitter 36, or light source, and a receiver 38. In an
alternate embodiment, the controller 34 is in electronic communication with the
drain valve 32 in order to automatically open or close the drain valve 32. The
controller 34 is an electronic device having a preprogrammed digital computer or
processor, control logic, memory used to store data, and at least one I/O section.
The control logic includes a plurality of logic routines for monitoring,
manipulating, and generating data. The controller 34 may be part of the control
for a motor vehicle or a separate module.
The emitter 36 is secured to the reservoir 16, as will be
described in further detail below. The emitter 36 is operable to emit a light beam
therefrom. The light beam is indicated by the arrow "A" in FIG. 1A and may be
coherent light or any other form of light. The emitter 36 may be any kind of light
source, such as, for example, a laser or light emitting diode. The emitter 36 may
emit the light beam continuously or it may pulse the light beam at predetermined
or random intervals for selected time periods. The receiver 38 is also secured to
the reservoir 16 and is located generally opposite the emitter 36. The receiver 38
is operable to detect the light beam emitted from the emitter 36. In the preferred

embodiment, the emitter 36 and receiver 38 are protected by a layer or coating of
non-corrosive materials, such as, for example, glass.
In the particular example provided, the emitter 36 and the
receiver 38 are coupled to an inner surface 40 of the reservoir 16. Alternatively,
the emitter 36 and the receiver 38 may be coupled to an outer surface 42 of the
reservoir 16 so long as the emitter 36 is able to emit the light beam through the
reservoir 16. This may be accomplished by employing a transparent reservoir 16
made from a material having a known index of refraction or by providing ports
through the reservoir 16 for the emitter 36 and receiver 38 to extend
therethrough.
The emitter 36 and receiver 38 are positioned within the
reservoir 16 such that the light beam is directed from the emitter 36 towards the
receiver 38. So long as any substance, such as fuel or air, located within the
cavity 28 has a constant index of refraction, the light beam emitted from the
emitter 36 will be detected by the receiver 38.
The controller 34 communicates with the emitter 36 to activate
the light beam and communicates with the receiver 38 to determine whether the
light beam has been detected by the receiver 38. If the light beam is directed
from the emitter 36 to the receiver 38 without interruption, then the receiver 38
will communicate with the controller 34 that the receiver 38 is detecting the
coherent light beam. This detection of the light beam is indicative that there is no
interruption of the light beam, indicative that there is no change of index of
refraction of the fuel within the cavity 28 of the fuel-water separator 12 and

indicative that the reservoir 16 does not need to be drained of water or
contaminants.
In an alternate embodiment the sensing system 10 includes a
plurality of receivers 39 located on the reservoir 16 opposite the emitter 36.
Alternatively, the receivers 38 and 39 may form one single strip sensor that
extends along the reservoir 16. The plurality of receivers 39 are in electronic
communication with the controller 34. Like the receiver 38, the additional
plurality of receivers 39 are operable to communicate with the controller 34 that
the plurality of receivers 39 are detecting the light beam. As will be described in
greater detail below, the plurality of receivers 39 will only detect the light beam
when the light beam has been redirected within the reservoir 16.
Turning now to FIG. 1B, if water is contained within the fuel as it
enters the fuel-water separator 12, this water will settle to the quiet zone 30 of
the reservoir 16 where the water will accumulate, as indicated by reference
number 44. The water 44 in part defines an interface 46 between the water 44
and any other substance, such as fuel or air, within the cavity 28. While water 44
is illustrated in the particular example provided, it should be appreciated that
various other contaminants may separate out of the fuel and behave in the same
manner as the water 44.
As the amount of collected water 44 increases, the interface 46
of the water 44 will rise towards the bottom surface 26 of the housing 12.
Eventually, the interface 46 of the water 44 will rise above the receiver 38 within
the reservoir 16, as is illustrated in FIG. 1B. Once the interface 46 of the water

44 has risen above the receiver 38, the water 44 will be in a direct line with the
light beam emitted from the emitter 36. As the light beam passes through the
interface 46 of the water 44, the light beam is refracted such that the light beam
is no longer directed towards the receiver 38. This refraction of the light beam
occurs because the water 44 has an index of refraction different from the index of
refraction of the fuel or air located within the cavity 28. For example, the fuel
within the cavity 28 has an index of refraction of approximately 1.44 while the
water 44 has an index of refraction of approximately 1.33. The position of the
receiver 38 with respect to the reservoir 16 determines how much water 44 is
allowed to accumulate before the light beam is refracted. In the example
illustrated in FIG.'s 1A and 1B, the receiver 38 is located near the bottom of the
reservoir 16 such that a small amount of water 44 within the reservoir 16 will
refract the coherent light beam. Alternatively, the receiver 38 may be positioned
on the reservoir 16 closer to the bottom surface 26 of the housing 14 to allow
more water 44 to accumulate before the water 44 refracts the light beam. In this
sense, knowing the location of the receiver 38 relative to the reservoir 16 allows
the sensing system 10 to know how much water has collected in the reservoir 16.
The light beam also may be attenuated if there is a change
in the transparency of the substance within the cavity 28. For example, if the fuel
suffers from gelling or clouding due to cold weather, the transparency of the fuel
will change, and the light beam will be attenuated such that it is not detected by
the receiver 38. Additionally, refraction may occur when water droplets falling
from the top of the reservoir 16 to the quiet zone 30 momentarily interrupt the

coherent light beam. Such momentary interruption of detection by the receiver
38 may be used to indicate early warning accumulation of water 44 within the
reservoir 16.
As noted above, the controller 34 communicates with the emitter
36 to activate the light beam and communicates with the receiver 38 to determine
whether the light beam has been detected by the receiver 38. If the presence of
the water 44 within the reservoir 16 refracts the light beam, the receiver 38 will
communicate with the controller 34 that the receiver 38 is not detecting the light
beam. This non-detection of the light beam is indicative of a problem within the
fuel-water separator 12. This problem may be that the water 44 within the
reservoir 16 should be drained by opening the drain valve 32 or that the fuel is
gelling or clouding due to cold weather. Once a problem has been detected, the
controller 34 may take various initiatives to alert an operator of the motor vehicle
of the problem or to take action to solve the problem. For example, the controller
34 may activate a water warning signal (either digital or analog), send an
electronic signal to the motor vehicle control to activate a engine warning signal,
automatically open the drain valve 32 using an electronically controlled actuator,
or automatically activate a heating element to warm the fuel.
In the embodiment where the sensing system 10 includes the
plurality of receivers 39, refraction or attenuation of the light beam can direct the
light beam towards one of the plurality of receivers 39. The plurality of receivers
39 then detects the light beam and communicates the detection to the controller
34. Control logic within the controller 34 can use the detection of the light beam

from a specific one of the plurality of receivers 39 to determine various conditions
within the reservoir 16. For example, the controller 34 may include a look-up
table of known indices of refraction for known substances that are often additives
of Diesel fuel such as kerosene or biodiesel fuel. As one of the plurality of
receivers 39 detects the light beam, the controller 34 may calculate the index of
refraction of the substance within the reservoir 16 based on which receiver 39
has detected the light, and use this calculated index of refraction to look up which
substance has a matching index of refraction. In this way, the sensing system 10
can determine not only that there has been an interruption of the light beam, but
it can also determine what kind of substance is located within the reservoir 16.
This may include what kind of fuel is being employed (such as what percentage
of biodiesel fuel, kerosene, etc.) or what kind of contaminants are in the reservoir
16 (such as water, sea water, etc.). The use of the plurality of sensors 39 may
also be used to determine the water level or contamination level within the
reservoir 16 based on the degree of the calculated index of refraction. The
controller 34 is operable to track the change in the index of refraction of the fuel
within the reservoir 16 over a period of time. The controller 34 may then
communicate the determined composition of the fuel to an engine controller (not
shown) which can then use the information to adjust combustion parameters.
With reference to FIG. 2, a second sensing system 100 is
illustrated with the exemplary fuel-water separator 12. The second sensing
system 100 includes a controller 102 in electronic communication with an
integrated light emitter/detector 104. A reflector 106 is positioned opposite the

integrated light emitter/detector 104. The controller 102 is an electronic device
having a preprogrammed digital computer or processor, control logic, memory
used to store data, and at least one I/O section. The control logic includes a
plurality of logic routines for monitoring, manipulating, and generating data. The
controller 102 may be part of the control for a motor vehicle or a separate
module.
The integrated light emitter/detector 104 is coupled to the
reservoir 16, as will be described in further detail below. The integrated light
emitter/detector 104 is operable to emit a light beam therefrom and is operable to
detect a returning light beam. The light beam is indicated by the arrow "A" in
FIG. 2A. The integrated light emitter/detector 104 may be any kind of light
source and light detector known in the art. The integrated light emitter/detector
104 may emit the light beam continuously or the integrated light emitter/detector
104 may pulse the light beam at predetermined or random intervals. The
reflector 106 is also coupled to the reservoir 16 and is located generally opposite
the emitter 36. The reflector 106 has a surface 108 operable to reflect the light
beam back towards the integrated light emitter/detector 104. In the preferred
embodiment, the integrated light emitter/detector 104 and the reflector 106 are
protected by a coating or layer of a non-corrosive material, such as, for example,
glass.
In the particular example provided, the integrated light
emitter/detector 104 and reflector 106 are coupled to an inner surface 40 of the
reservoir 16. Alternatively, the integrated light emitter/detector 104 and the

reflector 106 may be coupled to an outer surface 42 of the reservoir 16 so long
as the integrated light emitter/detector 104 is able to emit the light beam through
the reservoir 16. This may be accomplished by employing a transparent
reservoir 16 made from a material having a known index of refraction or by
providing ports through the reservoir 16 for the integrated light emitter/detector
104 and the reflector 106 to extend therethrough.
The integrated light emitter/detector 104 and the reflector 106
are positioned within the reservoir 16 such that the light beam is directed from
the integrated light emitter/detector 104 towards the reflector 106 which in turn
reflects the light beam back towards the integrated light emitter/detector 104. So
long as any substance, such as fuel or air, located within the cavity 28 has a
constant index of refraction, the light beam emitted from the integrated light
emitter/detector 104 will be reflected by the reflector 106 and in turn detected by
the integrated light emitter/detector 104.
The controller 102 communicates with the integrated light
emitter/detector 104 to activate the light beam and to determine whether the light
beam has been in turn detected by the integrated light emitter/detector 104. If
the light beam is emitted and detected by the integrated light emitter/detector
104, then the integrated light emitter/detector 104 will communicate with the
controller 102 that the integrated light emitter/detector 104 is detecting the light
beam. This detection of the light beam is indicative that there is no interruption of
the light beam, indicative that there is no change of index of refraction of the fuel

within the cavity 28 of the fuel-water separator 12 and indicative that the reservoir
16 does not need to be drained of water or contaminants.
Turning now to FIG. 2B, water 44 located within the reservoir 16
at a level above the reflector 106 has an effect similar to that described in FIG.
1A. Specifically, as the amount of water 44 that is collected increases, the
interface 46 of the water 44 will rise towards the bottom surface 26 of the housing
12. Eventually, the interface 46 of the water 44 will rise above the reflector 106
within the reservoir 16. Once the interface 46 of the water 44 has risen above
the reflector 106, the water 44 will be in direct line with the light beam emitted
from the integrated light emitter/detector 104. As the light beam passes across
the interface 46 of the water 44, the light beam is refracted such that the light
beam is no longer directed towards the receiver 38. This refraction of the light
beam occurs because the water 44 has an index of refraction different from the
index of refraction of the fuel or air located within the cavity 28. The position of
the reflector 106 with respect to the reservoir 16 determines how much water 44
is allowed to accumulate before the light beam is refracted.
The light beam also may be attenuated if there is a change in
the transparency of the substance within the cavity 28. For example, if the fuel
suffers from gelling or clouding due to cold weather, the transparency of the fuel
will change, and the light beam will be attenuated such that it is not detected by
the integrated light emitter/detector 104.
As noted above, the controller 102 communicates with the
integrated light emitter/detector 104 to activate the light beam and to determine

whether the light beam has been detected. If the presence of the water 44 within
the reservoir 16 refracts the light beam, the integrated light emitter/detector 104
will communicate with the controller 102 that the integrated light emitter/detector
104 is not detecting the light beam. This non-detection of the light beam is
indicative of a problem within the fuel-water separator 12. This problem may be
that the water 44 within the reservoir 16 should be drained by opening the drain
valve 32 or that the fuel is gelling or clouding due to cold weather. Once a
problem has been detected, the controller 102 may take various initiatives to alert
an operator of the motor vehicle of the problem or to take action to solve the
problem. For example, the controller 102 may activate a water warning signal
(either digital or analog), send an electronic signal to the motor vehicle control to
activate a engine warning signal, automatically open the drain valve 32 using an
electronically controller actuator, or automatically activate a heating element to
heat the fuel.
The description of the invention is merely exemplary in nature
and variations that do not depart from the gist of the invention are intended to be
within the scope of the invention. Such variations are not to be regarded as a
departure from the spirit and scope of the invention.

WE CLAIM
1. A fuel contaminant sensor comprising:
a fluid reservoir (16) for containing a first fluid and a second fluid, the
fluid reservoir having an inlet (18) and an outlet (20);
a light source (36) for projecting a light beam through the fluid reservoir
(16);
a light beam detector (38) for receiving the light beam projected through
the fluid reservoir (16); and
a controller (34) for activating the light source (36) and receiving an
output of the light beam detector (38);
characterized in that the first fluid and the second fluid define an interface
(46) between the first fluid and the second fluid, wherein the interface
(46) is disposed between the light source (36) and the light beam
detector (38), and the second fluid has an index of refraction different
than an index of refraction of the first fluid; and
in that an interruption of the light beam due to a change of index of
refraction between the first fluid and the second fluid at the interface (46)
inhibits the light beam detector (38) from receiving the light beam (36).
2. The fuel contaminant sensor as claimed in claim 1 wherein the light beam

is refracted when the interface is disposed above the receiver and below
the light source.
3. The fuel contaminant sensor as claimed in claim 1 wherein the
interruption is due to droplets of the second fluid passing across the path
of the light beam.
4. The fuel contaminant sensor as claimed in claim 1 wherein the light
source is positioned near a top of the reservoir and the detector is
positioned near a bottom of the reservoir.
5. The fuel contaminant sensor as claimed in claim 1 wherein the light
source pulses the light beam.
6. The fuel contaminant sensor as claimed in claim 1 wherein the light
source continuously emits the light beam.
7. The fuel contaminant sensor as claimed in claim 1 wherein the light
source is a laser.
8. The fuel contaminant sensor as claimed in claim 1 wherein the light
source is a light emitting diode.
9. The fuel contaminant sensor as claimed in claim 1 comprising a plurality
of light beam detectors located within the fluid reservoir.
10. The fuel contaminant sensor as claimed in claim 9 wherein the controller

comprises logic for calculating an index of refraction of the light beam
based on which of the plurality of light beam detectors has detected the
light beam and control logic for determining the substance within the fluid
reservoir based on the calculated index of refraction.
11. The fuel contaminant sensor as claimed in claim 10 wherein the controller
comprises logic to detect the change in the index of refraction of the light
beam over a time period.
12.The fuel contaminant sensor as claimed in claim 11 wherein the controller
comprises logic for communicating to an engine controller the composition
of the substance within the fluid reservoir over a period of time.
13.The fuel contaminant sensor as claimed in claim 9 wherein the controller
comprises logic for determining the amount of fluid within the fluid
reservoir based on which of the plurality of light beam detectors has
detected the light beam.
14.The fuel contaminant sensor as claimed in claim 1 comprising a drain
valve coupled to the fluid reservoir and controlled by the controller, the
drain valve operable to drain the fluid reservoir.
15.The fuel contaminant sensor as claimed in claim 14 wherein the drain
valve is opened by the controller when the light beam has been
interrupted.
16. A device for detecting a change in the contents of a fuel-water separator
comprising:

18.The device as claimed in claim 16 wherein the interruption is due to
droplets of the second fluid passing across the path of the light beam.
19. The device as claimed in claim 16 wherein the emitter/detector pulses the
light beam.
20.The device as claimed in claim 16 wherein the emitter/detector
continuously emits the light beam.
21.The device as claimed in claim 16 wherein the emitter/detector comprises
a laser.
22.The device as claimed in claim 16 wherein the emitter/detector comprises
a light emitting diode.
23.The device as claimed in claim 16 wherein the controller comprises logic
to detect the change in the index of refraction of the light beam over a
time period.
24.The device as claimed in claim 23 wherein the controller comprises logic
for communicating to an engine controller that the index of refraction of
the fluid has changed.



ABSTRACT


TITLE : "A FUEL CONTAMINANT SENSOR AND A DEVICE FOR
DETECTING A CHANGE IN THE CONTENTS OF A FUEL-WATER
SEPARATOR"
The invention relates to a fuel contaminant sensor comprising a fluid reservoir
(16) for containing a first fluid and a second fluid, the fluid reservoir having an
inlet (18) and an outlet (20); a light source (36) for projecting a light beam
through the fluid reservoir (16); a light beam detector (38) for receiving the light
beam projected through the fluid reservoir (16); and a controller (34) for
activating the light source (36) and receiving an output of the light beam
detector (38); the first fluid and the second fluid define an interface (46)
between the first fluid and the second fluid, wherein the interface (46) is
disposed between the light source (36) and the light beam detector (38), and
the second fluid has an index of refraction different than an index of refraction of
the first fluid; and in that an interruption of the light beam due to a change of
index of refraction between the first fluid and the second fluid at the interface
(46) inhibits the light beam detector (38) from receiving the light beam (36).

Documents:


Patent Number 259573
Indian Patent Application Number 346/KOL/2008
PG Journal Number 12/2014
Publication Date 21-Mar-2014
Grant Date 18-Mar-2014
Date of Filing 26-Feb-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER DETROIT, MICHIGAN 48265-3000
Inventors:
# Inventor's Name Inventor's Address
1 WILLIAM C. ALBERTSON 44472 RIVERGATE DRIVE CLINTON TOWNSHIP, MICHIGAN 48038
PCT International Classification Number G01N21/43
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/690,880 2007-03-26 U.S.A.