U.S. patent application number 15/409461 was filed with the patent office on 2017-07-20 for sensor system for multi-component fluids.
The applicant listed for this patent is Sentelligence, Inc.. Invention is credited to John Coates.
Application Number | 20170205338 15/409461 |
Document ID | / |
Family ID | 59314608 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170205338 |
Kind Code |
A1 |
Coates; John |
July 20, 2017 |
SENSOR SYSTEM FOR MULTI-COMPONENT FLUIDS
Abstract
A small scale and low cost spectral sensing system designed
primarily for multi-component fluids that provides a compact, low
cost platform for analyzers or chemical sensors with limited number
of optical and mechanical components featuring a light source, an
optical interface with the sample, and a custom detector
(multi-element). A single detector element has a specific
wavelength, defined by a filter that can be used to select and
measure specific chemical compounds. Multiple detector elements are
combined to create a multi-channel detector capable of measuring a
broad range of wavelengths from ultraviolet (UV) to near and
mid-infrared wavelengths. The fabricated sensor can be configured
for almost any class of material including gases, vapors, and
liquids, with extension to solids. This is linked to the use of the
custom detectors featuring filters tailored to specific substances
in a broad spectral range from the UV to infrared.
Inventors: |
Coates; John; (Newtown,
CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sentelligence, Inc. |
Carmel |
IN |
US |
|
|
Family ID: |
59314608 |
Appl. No.: |
15/409461 |
Filed: |
January 18, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62279859 |
Jan 18, 2016 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 21/85 20130101;
G01J 3/0291 20130101; G01J 3/36 20130101; G01J 3/457 20130101; G01J
3/0256 20130101; G01J 3/00 20130101; G01J 3/42 20130101; G01J
3/0205 20130101; G01N 21/8507 20130101; G01N 2201/08 20130101; G01N
21/255 20130101; G01N 21/359 20130101; G01J 3/0202 20130101 |
International
Class: |
G01N 21/31 20060101
G01N021/31 |
Claims
1. A system for determining in a sample a concentration of a
component of said sample, comprising: an integrated light source; a
detector system, wherein said detector system comprises at least
one detector element having an optical filter configured to detect
at least one pre-determined wavelength intensity of radiation
transmitted through the sample by said light source coupling
apparatus configured to position the detector system and integrate
light source; and integrated electronics, wherein said integrated
electronics comprise a processor in communication with the sensor,
the processor configured to calculate a value of the concentration
of the component in the sample based on the detected pre-determined
wavelength intensity.
2. The system of claim 1, further comprising a chamber configured
to permit the sample to pass through said chamber.
3. The system of claim 1, wherein said detector system is
configured to have multi-wavelength detection.
4. The system of claim 1, wherein said integrated light source is a
broad band wavelength emitter.
5. The system of claim 1, wherein said integrated light source
emits a wavelength between about 10 nm and about 26000 nm.
6. The system of claim 2, wherein said coupling apparatus is
configured to couple the light source and the detector system to
said chamber.
7. The system of claim 2, wherein said chamber has an insertion
probe having an adjustable measurement chamber and insertion tip,
wherein said probe is configured to allow a sample to enter into
said chamber from the insertion tip.
8. The system of claim 1, wherein said detector system has a
plurality of detector elements, each element having a unique
optical filter configured to detect a unique wavelength intensity
of radiation transmitted through the sample by said light
source.
9. The system of claim 1, further comprising a memory device in
communication with the processor for storing data.
10. The system of claim 1, wherein the coupling apparatus is
configured for coupling the light source and the detector system to
a measurement chamber.
11. (canceled)
12. A system for determining in a sample a concentration of a
component of said sample, comprising: an integrated light source; a
detector system, wherein said detector system comprises at least
one detector element having an optical filter configured to detect
a pre-determined wavelength intensity of radiation transmitted
through the sample by said light source a chamber wherein said
light source is positioned across from said detector system and
said sample passes through said chamber between said light source
and said detector system; a coupling apparatus configured to couple
said light source and said detector system to the chamber; and
integrated electronics, wherein said integrated electronics
comprise a processor in communication with the at least one sensor,
the processor configured to calculate, based on the detected
pre-determined wavelength a value of the concentration of the
component in the sample.
13. A remote sampling sensor for determining the characteristics of
a sample, comprising: a sample interface; a light emitter; a light
guide; a detector system; and integrated electronics.
14. The remote sampling sensor of claim 13, wherein said sample
interface is remotely located from said light emitter and detector
system.
15. The remote sampling sensor of claim 14, wherein said light
guide is solid.
16. The remote sampling sensor of claim 14, wherein said light
guide comprises a hollow conduit.
17. The remote sampling sensor of claim 14, wherein said sample
interface has a retro-reflective optic configured to return the
light from said light emitter to said detector system.
18. The remote sampling sensor of claim 17, further comprising a
fiber optic cable configured to return said light to the detector
system.
19. The remote sampling sensor of claim 14, wherein said detector
system comprises at least one detector element having an optical
filter configured to detect a pre-determined wavelength intensity
of radiation transmitted through the sample by said light
source.
20. The remote sampling sensor of claim 19, wherein said light
emitter is a broadband light source.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This U.S. Patent Application claims priority to U.S.
Provisional 62/279,859 filed Jan. 18, 2016, the disclosure of which
is considered part of the disclosure of this application and is
hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to optical sensors,
spectroscopy, and associated systems. More particularly, it relates
to optical sensors and systems that may be used, for example, for
the analysis and characterization of fluids.
BACKGROUND
[0003] Traditional "wet chemistry" test methods, such as
gravimetric or titrimetric methods, such as acid/base and KF
moisture titrations are commonly used in laboratories as standard
reference methods for determining the component concentrations of a
liquid sample. These methods are labor intensive and have a
significant cost burden because they require the need for reagents,
solvent and eventual waste disposal. While these methods are
common, and in many cases required for regulatory or reference
measurement reasons, they are considered undesirable and there is a
general movement away from them.
[0004] Optical spectral measurements for the monitoring of static
and dynamic fluid systems is well established in the field of
spectroscopy. Traditional systems may include the use of a
spectrometric measurement system, such as a spectrometer or
photometer, optically interfaced to a fluid stream, such as a
liquid or gas. In the case of spectrometer systems, commercial
dispersive near-infrared (NIR) or Fourier transform infrared (FTIR,
near- and mid-IR) instruments are usually used in transmission,
specular reflectance, transflectance (a combination of
transmittance and reflectance) and internal reflectance modes of
operation. These are very different approaches insofar as the
spectroscopy method relies on measuring the spectra of the key
components and then relying on spectral resolution or mathematics
to separate and measure the individual contributions from the
components.
[0005] Other traditional methods of analysis of multi-component gas
and vapor monitoring include gas chromatography (GC). Gas
chromatography physically separates the components by the
chromatograph and the separated components are measured directly
from the chromatogram by a suitable detection system; such as a
flame ionization detection (FID) system. This method can be very
expensive and may generate a significant service or operating
overhead when implemented in a continuous monitoring system,
particularly because GC requires the use of high purity compressed
gases). Similarly, mass spectrometry is another method for
multi-component gas and/or vapor analysis that works by measuring
the mass-to-charge ratio and abundance of gas-phase ions within a
high vacuum. This method is also costly and hard to reduce to a
scalable sensor that can be used for commercial sensing
applications.
[0006] U.S. Pat. No. 7,339,657 and published patent application
U.S. 2014/0226149 A1 by Coates et al., hereby incorporated by
reference in their entirety, discuss each of these modes of
operation as implemented into various optical sensor packages.
These examples feature near infrared light-emitting diodes (LEDs)
that are used for oil condition (soot level) and urea solution
quality measurements. The soot measurement is a simple photometric
measurement with one primary wavelength (940 nm), while the urea
quality sensor is a true spectral measurement with a three- or
four-point determination having two or three analytical
wavelengths, with about 970 nm and about 1050 nm, being the most
critical for water and urea, and one wavelength as a reference or
baseline, about 810 nm. In both cases attenuation of signal
intensity is used to compute the infrared (near-infrared)
absorption, which is correlated to the concentrations of soot (in
oil) and the relative concentrations of water and urea in the
binary mixture or solution.
[0007] However, these sensors are still limited in spectral range
by the wavelength specific LEDs. Additionally, these embodiments
require longer path lengths to efficiently and accurately measure
the samples, which requires the sensor package to be large and can
require a larger sample. These larger packages make it harder to
implement in certain applications, and may suffer from added
environmental interference with the sample. For example, a fluid
sample may freeze under certain conditions due to the larger
quantity of fluid needed to measure the sample.
[0008] More generally, optical spectroscopy, such as infrared
spectroscopy is a recognized technique for the analysis and
characterization of various types of fluids used in industrial,
environmental, automotive and transportation applications,
including solvents, fuels, lubricants, functional fluids, coolants
and diesel emission fluids such as aqueous urea solutions. Such
spectroscopic measurements can provide meaningful data about the
condition of the fluid and the fluid-mechanical system during
service. The term "infrared spectroscopy" is used in the broadest
sense, and includes both near infrared and mid-infrared, and covers
the region from about 700 nm to about 26,000 nm.
[0009] Infrared spectroscopy, as used and understood herein, can
provide measurement of fluid quality and other particular
properties. For example, fluids such as fuel or coolant may be
measured for properties such as oxidation, coolant contamination,
fuel dilution, and soot content. In most cases, this information is
derived directly as a measure of the chemical functionality, as
defined by the characteristic vibrational group frequencies
observed in the various forms of infrared spectra. Further, the UV
and visible spectra may provide information derived from color
and/or information derived from electronic transitions or coupled
vibrations, and can be applied to provide information about
oxidation, moisture and additive content, by way of example.
[0010] While the infrared spectral region is definitive in terms of
the measurement of materials as chemical entities, the measurements
can be difficult to implement in terms of the materials used. More
specifically, the optics and associated materials used in these
measuring devices are relatively expensive and do not always lend
themselves to easy replication for production scale analysis.
[0011] Moreover, when multiple devices are implemented into a
larger monitoring system used in, for example, industrial process
or automotive monitoring applications, these systems often become
prohibitively large, complex, and expensive. Another factor to
consider is the operating environment. If a monitoring system is to
be used in a relatively benign environment, such as in a laboratory
under standard ambient conditions or in a climate conditioned
indoor facility, then the known construction may be appropriate.
However, if there is a requirement to measure a fluid system in a
harsher environment, such as on a process line (indoors or
outdoors), on a vehicle, or a mobile or fixed piece of equipment,
then it is necessary to utilize a more robust system capable of
operating under such conditions. This may include considering the
temperature sensitivity of the components, as well as their
resilience to long-term exposure to continuous vibrations.
[0012] Additional factors for consideration include size, thermal
stability, vibration immunity, spectral range, and cost.
Alternative fluid measurement systems and techniques for fluid,
gas, and vapor sensing and monitoring that address one or more of
these considerations are desired. There exists a need for a more
compact sensor that can operate within a broader spectral range for
vapors, gases, liquid, and other materials, including solids or
mixed phase forms (e.g., emulsions, pastes, and foams).
[0013] The present invention can be used in a wide variety of
industries where liquid, gas and vapor sensing and monitoring is
critical, especially related to the analysis, in applications
requiring environmental, safety, and process considerations.
BRIEF SUMMARY OF THE INVENTION
[0014] In one aspect, this disclosure is related to a system for
determining in a sample the composition or concentration of a
component or components of said sample, comprising an integrated
light source; a detector system, wherein said detector system
comprises at least one detector element having an optical filter
configured to detect a pre-determined wavelength intensity of
radiation transmitted through the sample by said light source; a
coupling apparatus; and integrated electronics, wherein the
integrated electronics comprise a processor in communication with
the at least one sensor, the processor configured to calculate,
based on the detected pre-determined wavelength a value of the
concentration of the component in the sample.
[0015] In another aspect this disclosure is related to a system for
determining in a sample the characteristics of components of said
sample, comprising an integrated light source; a detector system,
wherein said detector system comprising at least one detector
element having an optical filter configured to detect a
pre-determined wavelength intensity of radiation transmitted
through the sample by said light source; a chamber wherein said
light source is positioned across from said detector system and
said sample passes through said chamber between said light source
and said detector system; a coupling apparatus configured to couple
said light source and said detector system to the chamber; and
integrated electronic, wherein said integrated electronics
comprises a processor in communication with the at least one
sensor, the processor configured to calculate, based on the
detected pre-determined wavelength a value of the concentration of
the component in the sample.
[0016] In yet another aspect this disclosure relates to a method
for determining the component characteristics of a sample,
comprising emitting at least one wavelength radiation by a
broadband emitting source. Detecting at least one intensity of
radiation transmitted through the sample by the source of at least
one reference wavelength. Determining the characteristics of the
components of a sample based at least in part on the at least one
detected intensity.
[0017] In another aspect this disclosure relates to a remote
sampling sensor for determining the characteristics of a sample,
comprising a sample interface, wherein said sample interface if
remotely located from said light emitter and detector system and
said sample interface has a retro-reflective optic; a light emitter
configured to emit a broadband wavelength of light; a light guide
configured to transmit emitted light to and from the sample
interface; a detector system, wherein said detector system
comprises at least one detector element having an optical filter
configured to detect a pre-determined wavelength intensity of
radiation transmitted through the sample by said light emitter; and
integrated electronics, wherein said integrated electronics
comprise a processor in communication with the at least one sensor,
the processor configured to calculate, based on the detected
pre-determined wavelength a value of the concentration of the
component in the sample.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The features and advantages of this disclosure, and the
manner of attaining them, will be more apparent and better
understood by reference to the following descriptions of the
disclosed system and process, taken in conjunction with the
accompanying drawings, wherein:
[0019] FIG. 1A is an illustration of an exemplary embodiment of
compact refractive optical elements that can be used for the sensor
of the present invention.
[0020] FIG. 1B is an illustration of an exemplary embodiments of
compact refractive optical elements that can be used for the sensor
of the present invention.
[0021] FIG. 1C is an illustration of an exemplary embodiment of
compact refractive optical elements that can be used for the sensor
of the present invention.
[0022] FIG. 2A is an illustration of a preferred embodiment of an
insertion probe sensor for location on a bulkhead.
[0023] FIG. 2B is an illustration of a preferred embodiment of an
insertion probe within a pipeline having flowing fluid.
[0024] FIG. 2C is an illustration of a preferred embodiment of an
insertion probe within a tank.
[0025] FIG. 3A is an illustration of an exemplary embodiment of an
in-line sensor.
[0026] FIG. 3B is an illustration of an exemplary embodiment of an
integrated in-line sensor head with close coupled dedicated
electronics.
[0027] FIG. 4A illustrates an exemplary embodiment of an immersible
transmissive sensor.
[0028] FIG. 4B illustrates another an exemplary embodiment of an
in-tank sensor for measuring both fluid level and composition of a
sample.
[0029] FIG. 5A is an exemplary embodiment of remote sampling
probes.
[0030] FIG. 5B is an exemplary embodiment with a fiber optic
coupling.
[0031] FIG. 5C is an exemplary embodiment of a sampling probe
configured for dip sampling in tanks with disposable elements.
[0032] FIG. 6 is NIR spectral data for refined hydrocarbon compared
to water for moisture measurements.
[0033] FIG. 7A is NIR spectral data for refined hydrocarbons and
fuel components.
[0034] FIG. 7B is another NIR spectral data chart for refined
hydrocarbons and fuel components.
[0035] FIG. 8 is NIR spectral data for fuels of petroleum and bio
sources, such as biodiesel and flex fuel.
[0036] FIG. 9A is NIR spectral data for aqueous based automotive
functional fluids, such as engine coolant Rotella.RTM..
[0037] FIG. 9B is NIR spectral data for aqueous based automotive
functional fluids, engine coolant and DEF urea solutions.
[0038] FIG. 10A is NIR spectral data for non-automotive, industrial
and petrochemical, solvents.
[0039] FIG. 10B is NIR spectral data for non-automotive, industrial
and petrochemical, solvents.
[0040] FIG. 11 is NIR spectral data for non-automotive; industrial
and petrochemical, polymers and plastics.
[0041] FIG. 12A is NIR spectral data for non-automotive; industrial
and agricultural grain ethanol production for biofuels and
beverages.
[0042] FIG. 12B is NIR spectral data for non-automotive; industrial
and agricultural grain ethanol production for biofuels.
[0043] FIG. 12C is a calibration curve for non-automotive;
industrial and agricultural grain ethanol production for
biofuels.
[0044] FIG. 12D is NIR spectral data for ethanol applications, such
as wine and spirits.
[0045] FIG. 13A is NIR spectral data for non-automotive; example
applications such as dairy.
[0046] FIG. 13B is NIR spectral data for non-automotive; example
applications such as seed oils.
[0047] FIG. 14 in NIR spectral data for non-automotive;
applications such as the pharmaceutical industry.
DETAILED DESCRIPTION OF THE INVENTION
[0048] It is to be understood that the figures and descriptions of
the present invention have been simplified to illustrate elements
that are relevant for a clear understanding of the present
invention, while eliminating, for purposes of clarity, many other
elements found in fluid measuring systems, including those
utilizing spectroscopy. However, because such elements are well
known in the art, and because they do not facilitate a better
understanding of the present invention, a discussion of such
elements is not provided herein. The disclosure herein is directed
to all such variations and modifications known to those skilled in
the art.
[0049] In the following detailed description, reference is made to
the accompanying drawings that show, by way of illustration,
specific embodiments in which the invention may be practiced. It is
to be understood that the various embodiments of the invention,
although different, are not necessarily mutually exclusive.
Furthermore, a particular feature, structure, or characteristic
described herein in connection with one embodiment may be
implemented within other embodiments without departing from the
scope of the invention. In addition, it is to be understood that
the location or arrangement of individual elements within each
disclosed embodiment may be modified without departing from the
scope of the invention. The following detailed description is,
therefore, not to be taken in a limiting sense, and the scope of
the present invention is defined only by the appended claims,
appropriately interpreted, along with the full range of equivalents
to which the claims are entitled. In the drawings, like numerals
refer to the same or similar functionality throughout several
views.
[0050] The term "processor" when used herein generally refers to a
circuit arrangement that may be contained on one or more silicon
chips, and/or integrated circuit (IC) boards, and that contains at
least one Central Processing Unit (CPU), and may contain multiple
CPU's. The CPU may generally include an arithmetic logic unit
(ALU), which performs arithmetic and logical operations, and a
control unit, which extracts instructions from memory and decodes
and executes them, calling on the ALU when necessary.
[0051] Processors may take the form of a microprocessor, and may be
a low power CMOS processor with an embedded analog to digital
converter, by way of non-limiting example only. The present
invention is operable with computer storage products or computer
readable media that contain program code for performing the various
computer-implemented operations. The non-transitory
computer-readable medium is any data storage device that can store
data which can thereafter be read or accessed by a computer system
component such as a microprocessor. The media and program code may
be those specially designed and constructed for the purposes of the
present invention, or they may be of the kind well known to those
of ordinary skill in the computer software arts. Examples of
computer-readable media include, but are not limited to magnetic
media such as hard disks, floppy disks, and magnetic tape; optical
media such as CD-ROM disks; magneto-optical media; solid-state
storage devices and specially configured hardware devices such as
application-specific integrated circuits (ASICs), programmable
logic devices (PLDs), and ROM and RAM devices. Examples of program
code include both machine code, as produced, for example, by a
compiler, or files containing higher-level code that may be
executed using an interpreter.
[0052] The term "electronics package" as used herein is to be
understood broadly and includes any configuration of electronic
components for use in providing power to components, such as light
sources and detectors, control signals to such components,
receiving data from such components, performing calculations and
signal processing on data received from such components, storing
received and processed data, and providing outputs of such data to
monitoring and display systems. Such packages may include discrete
analog and digital components, batteries, integrated circuits
configured to include multiple analog and/or digital logic
components, general purpose and special purpose processors, data
storage devices of all descriptions including magnetic, capacitive,
random access, read-only and other non-transitory storage media,
wireless and wired transmitters, receivers, and transceivers, and
other devices, in discrete and integrated form.
[0053] The detectors and emitters of all embodiments disclosed
herein may be integrated into and integrally formed with electronic
packages, such as on printed circuit boards such as control boards
of such packages. Alternatively, the detectors and emitters may be
configured to be mounted separately from control boards and other
electronic devices.
[0054] Fluid measuring/monitoring systems according to embodiments
of the present disclosure take into account factors of size,
thermal stability, vibration immunity and cost, and are configured
to facilitate mass production. Sensors and monitoring systems
according to embodiments of the present disclosure may simplify the
complex arrangements of the prior art by providing a broadband
wavelength light or energy source (or sources), a device for
interfacing with the sample, and one or more detectors. These
simplified spectrometric/photometric systems can be made relatively
small and compact compared to the large and expensive monitoring
systems of the prior art, while retaining their functionality and
reliability in harsh environments.
[0055] These systems may include the use of tungsten incandescent
light bulbs, gas discharge lamps, or solid-state light emitters
(e.g. LEDs or MEMs devices), low-cost, solid state detectors,
integrated with opto-electronics that reduce temperature dependency
effects, low-cost optics that may be mass-produced such as by
molding techniques (if required), and low-cost packaging. Residual
temperature effects may be handled by thermal modeling and the
application of compensation algorithms.
[0056] The sensor devices described in this disclosure may be
implemented as monitoring devices for water-based fluids, such as
aqueous urea solutions and coolants, in addition to fuels,
lubricants and other functional fluids used in automotive vehicles,
heavy equipment, and various forms of transportation that involve
dynamic fluid lubricant and power conversion systems. They may
include sensor devices for monitoring industrial processes and
maintenance, monitoring engine oils, transmission oils, hydraulic
oils and fluids, turbine oils, coolants and any fluid system that
protects mechanical moving parts or transmits power to moving
parts. Throughout the disclosure, the term fluid is considered in
the broadest sense, and can include gases and vapors, which include
off-gassing vapors from fuels, slip and bypass gases from
combustion zones, and exhaust gases. In one or more configurations,
the sensor can be operated immersed in the fluid, and measurements
can be made in a static environment such as a tank or storage
vessel, or in a moving environment, such as a fuel line or exhaust
pipe. It is understood that the period of measurement may vary from
less than a second, to a few seconds, to periods of days or longer,
such as for systems where the change in fluid composition
(chemistry) changes slowly, if at all. When used for fluid quality
assessment the sensor is intended to monitor for changes in
composition, including contamination from the use of an incorrect
fluid.
[0057] The concept represented here can be applied at very low cost
with a reduced number of optical and mechanical components
featuring a light source, an optical interface with the sample, and
the custom detector system. Some exemplary embodiments of the broad
band light source can include a tungsten light bulb, a composite
broad band LED such as a white LED or a gas discharge such as a
xenon, krypton, neon, deuterium or mercury light source. The
wavelengths can be defined by a custom, multi-element detector
system, where each detector element of the detector system is
combined with a light selecting element, such as a bandpass filter
or even a variable filter, as in the case of a multi-element
filter-detector combination. The light selecting element can select
for a pre-determined wavelength of interest. This exemplary
embodiment of the multi-wavelength sensing system overcomes
shortcomings of the previous applications by enabling a broader
range of wavelengths to be used. By addressing packaging issues,
different types of detector elements can be integrated providing a
truly multi-wavelength device that can have elements that are
sensitive in the UV, visible, near infrared and the mid-infrared,
all within a single mechanical package.
[0058] If one evaluates the full spectra from the UV to the NIR it
is possible to select filters that can provide specific detection
for virtually any chemical compound in liquid, solid, gas or vapor
form. Therefore, if one considers the application of dedicated
detectors as a spectroscopic application then multicomponent
chemical sensing can expand beyond the simple applications for
liquids and fluids. Combining one or more of these custom detectors
can be applied to a range of spectroscopic applications, especially
when used with spectroscopic software to perform complex analyses
for multicomponent chemical systems. In this way, the present
invention can be used as compact low cost analyzers or chemical
sensors developed for applications normally associated with the use
of high-priced instruments, such as FTIR spectrometers and gas
chromatographs.
[0059] When designed as a sensor, the sample interface can provide
the basic framework of the measurement system, where the light
source and detector system can be mounted on or within the
assembly. Such assemblies combine the source and detectors with the
support and control electronics to become a stand-alone device that
can function as an analyzer or an instrument. These can be
integrated or embedded into the measurement system, and provide an
output that is customized to the target application. When
implementing the user must understand the nature of the measurement
environment, such as the material being measured, its properties,
the operating environment in terms of temperature and pressure, and
how it can be optically coupled to the light source and detection
system. FIGS. 1 to 5 provide examples of suitable optical
interfaces that can be coupled to the basic sensor optical elements
(source and detector) and can be applied to a broad range of sample
types; liquids and solids.
[0060] Exemplary fluid monitoring systems are can be implemented
into an automotive, vehicular or heavy equipment application. As
set forth above, sensors according to embodiments of the present
disclosure may be suitable for fluid monitoring in all modes of
equipment operation. The present invention can be used for on-board
engine applications such as lubricant, coolant, aqueous urea
solutions (dosing into the SCR system) or on-board fuel monitoring,
a sensor may be located within a given fluid stream, such as in the
feed lines or in the fluid dosing system. Further, a sensor may be
configured as a submersible component located within a feed tank
(e.g. a urea solution tank or fuel tank).
[0061] Sensors according to embodiments of the disclosure may also
be used for oil condition monitoring (e.g. oxidation and nitration)
in gasoline and natural fired engines. For this application,
sensing devices may be located at the output side of an engine's
primary (or secondary) filtration system, where a filter is
inserted into the stream on the return side of the filter-housing
block. Advantages of mounting the sensor on the filter block
include convenient access, external mounting, and reduced operating
temperature. Alternative positions for the sensors described herein
may include the transmission, the coolant system or the rear axle.
Another possible sensor position is within a relatively cooler
location of the exhaust system, wherein a heat-insulated probe and
sensor can monitor exhaust gas for species such as NOx. While many
of the embodiments of the present disclosure are described in the
context of sensor devices installed on a vehicle or combustion
engine-powered system, these serve only as examples. The devices
are, as indicated, intended for use in all forms of fluid
measurement systems.
[0062] Referring generally, sensors according to embodiments of the
disclosure may also be used for a wide range of non-automotive
applications ranging from refinery applications, process plant
applications, power generation applications, including turbines,
and other transportation applications. Refinery applications can be
overlapped with other applications and can also include the
refining process, from the refining process at the front end to the
blending at the back end. Measurement of both the composition and
properties may occur during the processes as well as the products
of the processes, such as LPG (liquid petroleum gas), gasoline,
diesel, kerosene, etc. When used in turbines, the most
service-related issue leading to breakdown is gear box failure from
lubricant oxidation and degradation. Attempting to service a wind
turbine is very expensive because of the inconvenience of working
in the control house at the top of the turbine structure. Diesel
engine maintenance is important to prevent inconvenient breakdown
in remote locations away from service and maintenance facilities.
On-board sensors in both examples can monitor the lubricant quality
and provide onboard diagnostics broadcasted via wireless
communications.
[0063] In these exemplary embodiments, the present invention can
use a solid state light source 101, such as an LED, and a solid
state detector package, such as a standard photodiode detector 103
for detection. The photodiode detectors 103 and light source 101
can be packaged together on an opto-board 105 within the sensor.
This provides a low cost option and offers a non-species specific
measurement of fluids. This sensor can be based on a .about.400 nm
LED for NO.sub.2 and a .about.700 nm LED for a reference baseline.
This sensor can also be implemented with a remote insertion probe,
or the LED light sources may be mounted outside the sensor
enclosure and a measurement chamber 117 may be close coupled. A
coupling apparatus or sensor body 129 can be configured to couple
said light source 101 and said detector 103 proximate to the
chamber 117. The measurement chamber may have a light guide 107
using any suitable material, such as quartz, fused silica, or any
other material or combination thereof. The light path 109 can be
directed through the light guide 107. The measurement chamber 117
can be open and formed in between a void of the light guide
107.
[0064] FIGS. 1A-1C are illustrations of various embodiment where
the optical elements can be set on the tip of a probe that could be
immersed in the fluid for measurement. In other variations the
optics still apply, and the light source is a broadband,
multi-wavelength source, and the detector is a multi-wavelength
composite detector system, that can have individual detectors, each
with optical filters for different pre-determined wavelengths. This
provides a low cost construction and can be used for internal
reflectance and transmission methods of measurement. When properly
designed and concealed correctly this sensor can be applied to high
pressure applications where the tip of the sensor can be immersed
into a static or dynamic fluid flow, such as in an oil line, a
holding tank, hydraulic or cooling fluid line, or any other high
pressure environment.
[0065] The sensor shown in FIG. 2A takes the approach shown in
FIGS. 1A-1C one stage further, by packaging the sensing head to
hold it in place, and can provide a means of mounting and sealing.
An optical isolator 115 can also be used to isolate the light
source from the detector module 101, detector, or photodiode. This
exemplary embodiment can be implemented as an insertion probe
installed as a bulkhead style sensor fitting (2B and 2C). The
bulkhead embodiment can provide protection of the critical optical
sensor elements while providing an optical interface between the
internal optics and the fluid, which can be static (storage) or
dynamic (flowing).
[0066] A coupling apparatus for coupling said solid-state source
and solid-state detector to the measurement chamber can be used in
the real-time measurement sensor. The measurement chamber may also
include a single component optical interface fabricated as a
refractive optic 107 that works in an internal reflectance or
optional transmittance modes (or light scattering or fluorescence
modes). Integrated electronics 113 that include circuits that
provide optical compensation, temperature sensing and compensation,
analog and digital signal processing, and external communications
are communicatively coupled to the sensor. The integrated
electronics 113 can also be communicatively coupled to the
opto-board 105 or alternatively integrated as part of the
opto-board 105. The system is designed to allow a high level of
integration of both electronic and optical components, and to
include packaging that provides both thermal isolation and ease of
assembly and manufacture. Fiber optics or other forms of optical
light guide or light conduit may be used, with appropriate source
collimation and detector collection optical elements.
[0067] FIG. 2B and 2C are exemplary embodiments of a low cost
insertion probe embodiment of the present invention, which can have
close-coupled and combined electronics integrated with the sensor.
This embodiment can be used for coupling to fuel or lubricant
systems where the fluid enters the through the walls 121 of the
sensor body 129 of the probe and the light source energy passes
through the fluid. The returning energy is separated into
measurement channels of a measurement chamber 117 by the coupled
detector system 119 having at least one detector with an optical
filter. This type of sensing system can be fabricated for a minimal
cost and in a high volume. As shown, the device can function as a
stand-alone sensor, and can have embedded tools and analytical
members to provide a detailed analysis for lubricants (e.g., oil
condition), hydraulic fluids (e.g., quality and moisture content),
coolants (e.g., for quality and potential degradation) and dosing
fluids, such as urea solutions for SCR dosers. The embodiment in
FIG. 2B illustrates an embodiment where the fluid can flow through
the probe and put in line with hose or fluid line. The analytical
members of the sensor convert the optical signals from the
individual detector channels into results that directly correlate
with the properties being measured by the sensor. This can include
properties, such as but not limited to, quality (e.g., degradation
of oils, or the grade of fuels), levels of contamination (e.g.,
moisture content, hydraulics) or component concentration (e.g.,
urea in SCR dosing fluids or glycol in coolants)
[0068] FIGS. 3A and 3B, are exemplary embodiments of sensors
described in the present disclosure implemented as in-line flow
through packages, similar to the embodiment illustrated in FIG. 2A.
For example, FIG. 3A is a cross-sectional view illustrating an
in-line (flow-through) sensor with an adjustable retro-reflective
insert, and an electronics package/opto-board 105 including at
least one light source 101 and at least one detector 103. This
interchangeable insert may be used for fine adjustment of the
optical path length 109, or reflector type, without the need to
replace the entire sensor package. As illustrated, energy from
light source 101, which is typically a broadband light source
emitting multiple wavelengths, passes through the fluid in the
chamber 117 and back to detector 103 along the path shown 109 in
FIG. 3A. The transmitted energy, which can include deep UV to the
upper limits of the infrared spectrum interacts with the sample
fluid, with the characteristic absorptions of the fluid modifying
the light transmission of the fluid, and is subsequently sensed by
a detector system, having at least one detector. The in-line flow
through sensor allows a fluid to flow through the sensor and
measurement chamber while the sensor is in operation. The fluid
path 123 is illustrated in FIG. 3A and flows through a first end of
the sensor through to a second end of the sensor. The selectivity
of the absorption is defined by the optical filters integrated with
the individual detectors of the detector system. The detector
system can include a plurality of detectors each with an optical
filter for different wavelengths.
[0069] FIG. 3B is another exemplary embodiment of an in-line flow
through sensor that can be optimized for the mid-wave and longer
wavelength NIR where a path length of about 10 mm or is necessary
to be suitable to the application. This sensor can include
connectors 125 in communication with chamber for interfacing with a
fluid feed path (e.g. a fuel line). This complete package can
include a close coupled electronics interface and can have about
8-channels available for the monitoring of about 8 independent
wavelengths. This smaller path length can allow the sensor to be
packaged even smaller and requires a smaller sample size that can
aid in preventing environmental factors, such as freezing, from
affecting the sample.
[0070] The sensor can use any suitable coupling 125, such as a
standard Swagelok.RTM., Circor.RTM. or Parker.RTM. style
compression coupling, which can be attached to an inner chamber 117
and fitted with sealed windows. The sealed windows can use any
suitable material, such as quartz, sapphire, barium or calcium
fluoride. The light source 101 and detector 103 can be juxtaposed
to optimize optical coupling. Additionally, the electronics can be
close-coupled to reduce connector wire lengths and minimize signal
pickup. The entire package is optimized for size and
optical/pneumatic efficiency for gas measurements.
[0071] The integrated reflective sensor embodiments shown in FIGS.
2A-2C and FIGS. 3A-B may have a challenge interfacing with fluids
depending on location or representative sampling for the
measurement. Other applications may have few limitations in terms
where the sensor has to be placed, such as the case where the fluid
is stored in a tank and the sensor can be submersed in the fluid.
This can be beneficial for applications where the sensor ideally
should be used at a temperature close to that of the fluid. FIG. 4A
is an exemplary embodiment where the electronics and the optics can
be in a package that can be used as a submersible sensor within a
storage or dispensing tank. This sensor can operate in a "staring"
mode, wherein an electronics package 113 can include a broadband
light source 101 and a detector system 103 that can have a
plurality of detector elements with optical filter for various
specific wavelengths. The light source 101 and detectors 103 can be
generally located opposite one another, between which is arranged a
sensing area or measurement chamber 117. While the sensor can be
used as a submersible sensor that can be located within, for
example, a fluid dosing tank, it can also be integrated into a
flow-through system. The sensor can also include molded lenses 127
to protect the light source 101 and detector 103 from direct
exposure to the fluid. The sensor can have a molded enclosure 129
that packages the light source 101, detector 103, and integrated
electronics 113 and configured in a way to position the light
source 101 and detector 103 opposite of each other to form the
sensing area 117. It can also allow for connection to a power
source 131.
[0072] In one alternative in-tank embodiment of the present
disclosure for measuring both fluid level and fluid
quality/composition in an in-tank application. Similar to the
embodiment illustrated in FIG. 4B, in this staring mode embodiment,
the path length is defined by the volume of fluid in a tank and the
anticipated depth of fluid. In this embodiment, the depth to be
measured may be of a liquid, and not of a gas, the volume above the
level of the liquid being of gases. More specifically, sensor is
housed in an elongated porous body or housing 133, which may be in
the form of a hollow tube, which may be cylindrical. The active
components, a light source 101 of the sensor may be mounted at the
lower end of housing. The receiver or detector 103 may be arranged
on an opposite end, for example, at the top of tank with the
associated control and data processing electronics 113. The light
source 101 and detector 103 may be so arranged and oriented that
the light source transmits radiation along body from one end to
another, and may further in an embodiment transmit radiation
through the hollow interior or sample chamber 117 of the body 133
to detector 103. The sensor can also include molded lenses 127 to
protect the light source 101 and detector 103 from direct exposure
to the fluid.
[0073] The mounting of the light source 101 within the hollow body
133 may tend to protect light source against physical shock. Wiring
to transmit power and control signals to light source may be within
the hollow body; in embodiments, light source 101 may be packaged
in a sealed unit including one or more batteries or other internal
or external source(s) of power. In this embodiment, the absolute
absorption measured may be correlated initially to path length or
depth of fluid, and the relative absorptions of the fluid
components are determined and correlated to the ratio(s) of the
main components. More specifically, sensor may be used in a
measuring process for determining the depth of a volume of fluid.
In one embodiment, a light source is operative to transmit light
energy through a volume of fluid. This energy is subsequently
detected by a detector 103. A comparison can be made between the
magnitude of energy transmitted by the light source and the
magnitude of the energy received by detector to calculate energy
absorbed by the fluid. Finally, this absorption value is compared
to a predetermined absorption vs. depth relationship, which may be
stored in a memory device incorporated in electronics, for
estimating or determining the depth of the fluid. This estimated or
determined depth value may be output to, for example, a display
device. As will be understood by one of ordinary skill in the art,
these calculations may be performed by processing components
incorporated into the control electronics (e.g. electronics).
[0074] A remote sampling sensor embodiment of the present invention
is shown in FIGS. 5A-5C. In this embodiment a sample interface can
be used for making the measurement head remote from the measurement
optics. The measurement head being remote from the electronics of
the sensor can be beneficial if the measurement point is inside a
large piece of equipment, or if the actual measurement is to be
made at elevated temperature or in an "alien" environment where it
is beneficial to isolate the measurement components (optics and
electronics) remote from the fluid or gas stream. FIG. 5C is a
variant of this concept where the optical probe can be used in a
"dipping" configuration, and where disposable elements can be added
to make the probe reusable or maintained clean, free from
contamination.
[0075] FIG. 5A is the most basic form of implementation where the
light from the source 101 is transmitted down a solid light guide
107 or conduit through the fluid to a retro-reflective optic 135,
where the beam is returned to the composite detector 103
(filter/detector combination). FIG. 5B is a variant of the design
shown in FIG. 5A where the light from the source 101 is transmitted
down a hollow conduit or light guide 107, and the returned
retro-reflected light is transmitted back to the composite detector
via a fiber optic cable 137. FIG. 5C provides an optional form of
this concept where the optical probe can be used in a "dipping"
configuration, and where disposable elements, such as a disposable
tip 139 having the reflective optic 135 and a disposable sleeve 141
enclosing at least a portion of the light guide 107 can be added to
make the probe reusable or be maintained in a clean condition,
effectively free from contamination. In this exemplary embodiment
the external surfaces of the dipping probe are protected by a
removable and optionally a disposable covering or sheath. This may
be useful where cross-contamination of fluid may occur within the
sampling process, or where the fluid may be corrosive and the
sheath provides protection.
[0076] Several of these implementations can be equally applied to
gases and solids, as powders and sheets of materials. The main
spectral regions covered by this invention are the start of the
visible to the end of the near infrared, effectively about 350/400
nm through to about 2500/2600 nm, but can also extend into the UV
to far UV range as well (about 190 nm--about 400 nm). One of the
first applications than the present invention can be applied to
fluid condition monitoring of hydraulic fluids. One of the most
important measurements is for moisture or water ingress where an
environmental seal has failed, and where traces of water/moisture
enter the oil system leading to further seal failure, which can
cause leakage or corrosion. The spectra shown in FIG. 6 illustrate
the clear differentiation between the water spectrum and the
hydrocarbon spectrum of the lubricant/hydraulic fluid. This type of
sensor, which can be implemented as either in a flow-through FIGS.
3A and 3B or a bulkhead FIGS. 2A-C configuration, can located in
both high and low pressure locations of hydraulic system. Other
properties can be measured, including oil/fluid degradation and the
presence of particulates and debris.
[0077] One of the important benefits of the new version of the
technology is the broad spectral range that can be covered.
Measurement of liquid mixtures is an important area of application
and measuring over a broad wavelength range allows for materials in
mixture to be easily differentiated, and this is important for
applications such as the onboard measurement of fuel components and
fuel quality. FIG. 7 illustrates and comparing two of the important
hydrocarbon components, representing aliphatics (naphtha) and
aromatics. Onboard a vehicle, such differentiation can be used for
the switch-over from normal petroleum fuels and bio sourced fuels,
which can provide important fuel performance differentiation. A
simple, low cost version of the spectral sensor (4- or 8-channel
versions) can be used as an inexpensive onboard analyzer
systems.
[0078] FIG. 8 illustrates the NIR spectral data for fuels of
petroleum and bio sources, such as biodiesel and flex fuel.
Lubricant, fuel and fluid monitoring applications are good
applications for a quality monitoring system on board a vehicle.
There are other important fluids on board a vehicle and their
quality is also important. In the case of coolants, loss of water
or coolant can be indicative of an important service related issue,
such as failure of a coolant system, or contamination by coolant
can lead to catastrophic mechanical failure. In yet another
application, the sensor can be used for monitoring of the quality
of dosed fluids such as aqueous urea solution (FIG. 9), used in
modern HD diesel engines to reduce NOx emissions. Both fluids can
be easily monitored for quality by the use of a NIR based spectral
sensor. Gasoline, diesel, B50, and B100 all have a very similar
spectral absorbance at similar wavelengths. Gasoline has a slightly
different absorbance than the level at similar wavelengths to the
other three. The 10% ethanol primary absorbance occurs at a 1600 nm
rather than around 1400 nm like the other fuels.
[0079] The present invention can focus on automotive fluid
monitoring for lubricants, fuels and other functional fluids, such
as coolants in FIG. 9A and 9B. Both water and Rotella cooling fluid
have very similar spectral readouts. The sensors are important in
other areas of application, in particular for in-line and on-line
process monitoring for production related applications. This is an
important shift in focus for manufacturing production and process
control where the real-time analysis of liquid or gas related
processes are handled by complex high cost measurement systems. A
typical monitoring system features complex instrumentation combined
with difficult to implement sample handling and interfacing. The
systems described in this disclosure are fully integrated
measurement systems that integrate the optics, sampling interfacing
and electronics to provide a low-cost and versatile measurement
system that can implemented in many different locations within a
process. THE DEF coolant have very similar spectral readouts as
water, however, the DEF solutions have absorbance peaks around 2200
nm.
[0080] FIGS. 10-12 present the spectral data from important
non-automotive applications of the spectral sensing systems for
commercial applications that include chemical production for
important organic liquids and solvents (FIG. 10), plastics and
polymers in FIG. 11 and alcohol production FIGS. 12A-D, which are
an important industrial manufacturing process. The spectral sensor
presented can easily be implemented for common manufacturing
process, similar to those indicated by the spectral data, and at a
cost of a few hundred dollars compared to multiple thousands of
dollars for conventional sensors and instrumentation. An exemplary,
important area of application for plastics where rapid, low cost
differentiation is required is for waste disposal and for
recycling. There are multiple areas of application for this class
of spectral measurement.
[0081] These are typical analyses that lend themselves to
measurements by simple spectral sensors. Because of the benefits
associated with multiple wavelength measurement capability, and the
low cost implementations, the sensor technology can be considered
for applications outside of the scope of normal automotive and
industrial sensing. Three such areas of applications are indicated
in FIGS. 13A-B and 14.
[0082] Dairy products are a classical adaptation of spectral
analysis where milk quality, from the farm to the home, is
monitored and measured by spectral methods. The availability of
simple spectral sensors for milk production is an important
advancement where there is the potential to determine milk quality
at the dairy farm by literally placing sensors within the milking
machine. Vegetable and seed oils are important classes of materials
that can be measured and differentiated by spectral methods.
Applications include quality assessment in food-grade liquids, such
as extra virgin olive oil where a premium can be paid for the
highest quality product and the detection of counterfeits where
lower grade oils are substituted for higher quality grades. Another
area the sensor can be used for is in characterization of drugs and
pharmaceutical compounds. Providing the home with a low cost tool
for characterizing drug products is one of many future applications
for low cost spectral sensing.
* * * * *