In-situ spectral process monitoring

Increasing the precision of process monitoring may be improved if the sensors take the form of travelling probes riding along with the flowing materials in the manufacturing process rather than sample only when the process moves passed the sensors fixed location. The probe includes an outer housing hermetically sealed from the flowing materials, and a light source for transmitting light through a window in the housing onto the flowing materials. A spatially variable optical filter (SVF) captures light returning from the flowing materials, and separates the captured light into a spectrum of constituent wavelength signals for transmission to a detector array, which provides a power reading for each constituent wavelength signal.

BACKGROUND

Manufacturing processes used in the preparation of pharmaceuticals, food, distillates and chemical compounds may include some type of sensor inspection of the mixing process, for example, spectral, pH, and thermal interrogation. These sensors are typically attached to a wall of a processing vessel, and monitor parameters of the process using a probe protruding into the manufacturing process. However, the stationary nature of sensors having a fixed position limits inspection capabilities to the product in the immediate vicinity of the sensor's fixed position and may not provide information about other parts of the process.

A collimating element may be required prior to variable optical filters to prevent the spectral selectivity of the linearly variable filter from being degraded. Degradation may happen because the optical filter may include a stack of thin dielectric films, and the wavelength-selective properties of thin film filters are generally dependent on the angle of incidence of incoming light, which may deteriorate spectral selectivity and wavelength accuracy of thin film filters. However, for the device in the present disclosure it may be beneficial to reduce the size of the spectrometer even more by eliminating bulky lenses.

DETAILED DESCRIPTION

Spectral evaluation at various times and locations in a flowing material, such as liquids, powders and gas, provides powerful process monitoring capabilities.FIG. 1is a diagram of a top view, andFIG. 2is a diagram of a cross-sectional view of a probe1according to an example implementation described below. The probe1may be a spatially variable filter (SVF) based spectral probe and includes an outer housing2, which may be monolithic or multi-sectional in form and may be hermetically sealed, thereby making the probe1robust for applications in which it is immersed in a material the probe is to measure. The outer housing2may take one of several shapes or combinations thereof including, but not limited to, spherical1(FIGS. 1 and 2), toroidal1A (FIG. 3A), rounded toroidal1B (FIG. 3B), ellipsoid or prolate spheroid (football)1C (FIG. 3C), and cylindrical1D (FIG. 3D) depending on the application. In one example implementation, the outer housing2may be made of or include a corrosion-resistant material, such as stainless steel or a polymer material.

The outer housing2may include one or more windows4spaced apart on the outer housing2or the outer housing2may be entirely transparent, i.e. a continuous window. In various example implementations, the outer housing2may include any of 1 to 20 or more windows4. The one or more windows4enable light reflected or refracted from the surrounding material to be captured by a corresponding linearly or spatially variable optical filter (SVF)7inside the probe1. The reflected or refracted light may originate from one or more internal light sources6, an external light source (not shown), ambient light, or a combination thereof. The SVF7may be discrete or continuously varying. The filter7may be based on other dispersive elements, e.g. gratings, or prisms, or may be based on other technology, such as MEMS, dyes and pigments, FTIR, and Raman. The SVF7separates the captured light into a spectrum of constituent wavelength signals for analysis.

The windows4may be made of any suitable material, which is optically transparent for the desired transmission and reflected or refracted wavelengths, e.g., sapphire, silicon, Teflon, glass, etc. The internal light source6may be any suitable light source, e.g., a tungsten or LED light source, for transmitting the required wavelength band of light, e.g., visible (350 nm to 900 nm) and/or near infrared (NIR). In an example implementation, for near infrared, the light source6may be comprised of one or more onboard incandescent lamps, e.g. vacuum tungsten lamps, that provide broadband illumination, e.g., over 500 nm, over 700 nm, or over 1000 nm across the active range of the instrument, e.g., for the NIR in the 900 nm to 1700 nm range or in the 900 nm to 2150 nm range. One lamp6is sufficient; however, two lamps provides more light for the sample to interact with, hence shorter integration times.

In an example implementation, as illustrated inFIG. 2, a conduit19extending from an opening in the outer housing2into the outer housing2to an outlet in the outer housing2may be provided enabling the passing of the flowing material, e.g. liquid, in between the light source6and the SVF7within the outer housing2for generating a transmission spectrum via the photodetectors8and the controller12. The entire conduit19may be transparent to the transmitted light providing the necessary window for light to be transmitted from the light source6to the SVF7, or one or more sections of the conduit19may be transparent providing the required window(s) for transmitted, refracted or reflected light.

Mounted beneath each SVF7is an array of photodetectors8forming a spectrometer15and generating a power reading for each constituent wavelength signal, thereby providing a spectrum of the reflected light. Each of the spectrometers15in each probe1may have a same spectral range or different spectrometers15may have different spectral ranges, e.g., overlapping or adjacent, to enable a broad spectral range to be stitched together from the individual spectrometers15. Another example implementation may include a plurality of fiber bundles, each connecting to a single spectrometer15for light supply and data collection. Each bundle may communicate with a different window4, and may be sequentially coupled to the single spectrometer15.

The photodetectors8may be a broadband detector array, e.g. more than 500 nm, more than 600 nm, or more than 700 nm wide, such as an indium gallium arsenide (InGaAs) detector covering 950 nm to 1650 nm, which may be extended to 1150 nm to 2150 nm, if desired or required. For multiple spectrometer probes1and multiple probe systems, different spectrometers15within each probe1and different probes1within each system may have light sources6, filters7and photodetectors8with different spectral ranges to cover a wider spectrum, e.g. ultraviolet to infrared, to enable a broad range of tests.

An inner frame11may be mounted inside the outer housing2for supporting all of the SVF's7and photodetector arrays8. The inner frame11may be made of or include one or more of a printed circuit board material, plastic, metal, ceramic, or other suitable material. A controller12may be mounted within or on the inner frame11. The controller12may comprise suitable hardware, e.g., processor and memory chips mounted on printed circuit boards13, along with suitable software for controlling all of the probes features, including spectrum generation, storing, and analysis, thereby providing a self-contained spectral probe1for immersion in the material, in particular when the material is moving or flowing in production.

Other types of sensors14that may be included within the probe1include, but are not limited to, pH sensors, temperature sensors, pressure sensors, voltage sensors, velocity sensors, accelerometers, gyroscopes, and onboard cameras and forward looking infrared (FUR) sensors. In various example implementations, the probe1may include multiple similar and/or different sensors positioned around the outer housing2of the probe1. These multiple sensors14can enable multiple data sets to be interrogated and improve the quality of the various measurements. Each of the sensors14along with the photodetector arrays8are connected to the controller12for control and data storage.

Each probe1may include one or more shutters16within the outer housing2, presenting calibration standards that moves into and out of location in front of each spectrometer15as part of a calibration process. In the example implementation illustrated inFIG. 2, the shutter16is mounted on the end of a rotating arm17, which rotates about a central anchor18connected to the inner frame11. The shutter16may recalibrate each spectrometer15after a predetermined time, e.g., at least every 5 minutes of operation, or after a predetermined number of uses, e.g., at least after every 300 spectral readings.

The shutter16includes a calibrated reflectance standard to be rotated between the light source6and the window4to reflect the light from each light source6directly to the corresponding SVF7. The reflectance from this known standard is then compared to previous tests to determine any change in illumination inside the probe1.

A communication module21is provided to enable control and/or data signals to be sent between the controller12and a base station (shown inFIGS. 7 to 9). In an example implementation, the base station may be monitored by process monitoring engineers. In another example implementation, the base station may include an automated process control system. The communication module21may be one or more of a wireless transceiver, a tethered communication cable connection, a photo transceiver, or an acoustical transceiver. A communication module21that is wireless may require antennas (not shown) positioned within or outside the outer housing2to achieve a real-time data transfer connection with the base station.

The probe1may be self-powered with the use of replaceable of rechargeable batteries22and/or may be powered by a tethered power cable24adjacent to or coordinated with the optional communication cable connection (not shown). The power cable24may act as a communication line interconnecting the communication module21with the base station, and a tether for retrieving the probe1from the flowing media. Since the outer housing2may be hermetic, in an example implementation, the batteries22may be recharged using an induction connection. In an example implementation, the controller circuit12may employ the use of a position system tracker (not shown), e.g., a global positioning system (GPS), to track the location of the probe1within the manufacturing or monitoring process. Another possible position tracking system comprises a radio transmitter (not shown) in the probe1for signaling an array of fixed directional radio receivers (not shown) positioned around a processing vessel. The array of fixed direction radio receivers may be used to coordinate the position of the probe1within the fixed processing vessel or system, whereby the base station and/or each probe's controller12may determine the probe's position. An inertial measurement unit (IMU) (not shown) may also be provided to enable the controller12or the base station to monitor the probe1for orientation and direction of travel within the process vessel.

In one example implementation, the probe1may be compatible with the process it is intended to interrogate, for example, the outer housing2may be made of IP67 or higher plastic NEMA 4, or the like, for package hermiticity and dust ingress and compatible chemical resistance from the material it is immersed in. In an example implementation, the probe1may have variable buoyancy to adjust its buoyancy for use in a liquid process. As stated earlier, the probe1may be free to move within the process or may be attached to a fixed object via tether for post process retrieval.

In an example implementation, the outer housing2may be ruggedized to handle impacts from mixing or pressurized actions within the manufacture process. In an example implementation, the probe1may be used in a process that requires extended monitoring times and the controller12may include programming to instruct the photodetector arrays8and sensors14to change into low power “Stand by” modes to conserve power during long process cycles.

FIG. 4is a diagram of an isometric view of a probe1according to an example implantation described below. The outer housing2of the probe1may include structural features that facilitate movement and stability with and through the material in which the probe is immersed. The structural features may include, for example, dimples, small or large ribs, stubs, semi-circular or rectangular ribs, veins, or fingers. The example implementation probe1inFIG. 4includes a number of ribs3. The structural features may provide protection for the probe1from contact with other objects, e.g., vessel walls. The structural features may also provide enhanced mixing and/or reduced clumping within the flowing material as the probe1travels through the flowing material. The structural features may also help in maintaining orientation of the probe1relative to the direction of the flow of the material in which the probe1is immersed, facilitate heat exchange with the material, and direct the material to be measured in front of the sensor windows4for measurement and for removing debris that may have become adhered thereto.

The outer housing2may also include a hatch9for accessing a storage compartment10. The hatch9may be opened by the controller12in response to a signal from the base station or in response to an internal signal from the controller12, e.g., a spectrum reading or other test signal reaching a predetermined or desired level. In an example implementation, the storage compartment10may contain a substance used to facilitate a chemical process, e.g., a catalyst. In an example implementation, the storage compartment10may contain a substance used to mark a specific location, e.g., a dye. In an example implementation, the storage compartment10may contain a substance used to alter the chemical parameters of the substance in which the probe1is immersed, e.g., pH or toxicity. Alternatively, the hatch9may be opened in response to a signal from the controller12and/or the base station to capture fluid from the material in which the probe is immersed in the storage compartment10for further testing or for controlling buoyancy of the probe1.

The probe1may also include a separate buoyancy system31, which will enable the buoyancy of each probe1to be individually adjusted before insertion into the flowing material or during active monitoring in the flowing material to enable the probe1to be guided or propelled to a different location, and different depths within the flowing material. The buoyancy system31may comprise a fluid expelling device for expelling fluid from a storage tank or bladder32, thereby decreasing the density of the probe1and/or a fluid intake device for capturing surrounding fluid, thereby increasing the density of the probe1.

The probe1may also include a propulsion system33, which will enable the position of each probe1to be adjusted by the controller12and/or the base station. The propulsion system33may include the release of a pressurized burst of fluid stored in a storage tank, an electro-magnet, which may be energized to attract the probe1towards a metallic structure in the processing tank, or a propeller.

In certain applications, a window cleaner system25, which may be controlled by the controller12, may be provided to periodically wipe or remove accumulated material off of the exterior of the windows4. The cleaner system25may comprise an external concentric shell (not shown) with a wiper system mounted on the outer housing1. The wiper system may include a wiper26mounted on an a rotating or translating arm27which may be swept across the windows4. Alternatively or in addition to the wiper system, the propulsion system33may spin the probe1at high speed within the volume of flowing material to throw off any accumulated material on the windows4by centrifugal force. Other cleaning systems may include one or more of a sonic agitator to provide sonic agitation to clear the windows4, a heater to heat the windows4and to drive off moist powders, and a source of electricity to generate an electric discharge.

FIG. 5is a diagram of a side view of a dual SVF filter according to an example implementation described below.FIG. 6is a diagram of a side view of a spectrometer according to an example implementation described below. The spatially variable filter (SVF)7comprises a center wavelength of a passband varying, e.g. linearly or non-linearly, along an x-axis, and in some embodiments in the y-axis forming a 2D spatially variable filter (SVF).

Accordingly, the SVF7may include sequentially disposed upstream35A and downstream35B spatially variable bandpass optical filters (SVF) separated by a predetermined fixed distance L in an optical path36of an optical beam37, as disclosed in U.S. patent application Ser. Nos. 14/608,356 and 14/818,986, entitled “OPTICAL FILTER AND SPECTROMETER” by Smith et al, filed Aug. 5, 2015, which are herein incorporated by reference. The upstream SVF35A and the downstream SVF35B each have a bandpass center wavelength λTvarying in a mutually coordinated fashion along a common first direction38represented by the x-axes. The first direction38is transversal to the optical path36. By way of a non-limiting example, the bandpass center wavelength λTof both the upstream35A and downstream35B SVF have respective monotonic, linear dependences. The configuration of the optical filter7enables a dependence of spectral selectivity of the optical filter7on a degree of collimation of the optical beam37to be lessened as compared to a corresponding dependence of spectral selectivity of the downstream SVF35B on the degree of collimation of the optical beam37.

In the example ofFIG. 5, the upstream35A and downstream35B SVF are aligned with each other, so that the reference point x0corresponding to the reference bandpass center wavelength λ0of the downstream filter35B is disposed directly under the reference point x0corresponding to the reference bandpass center wavelength λ0of the upstream filter35A. The upstream filter35A functions as a spatial filter for the downstream filter35B, defining a predetermined or preset angle of acceptance39for the downstream filter35B. The angle of acceptance39is limited by left40L and right40R marginal rays at the reference wavelength λ0, each propagating at the angle θ to a normal36to the upstream35A and downstream35B filters and striking downstream filter359at the same reference point x0. The angle of acceptance30may be derived from a passband41A of the upstream filter35A as follows.

In the geometry illustrated inFIG. 5, the left marginal ray40L strikes the upstream filter35A at a location x0-Δx. Transmission wavelength λL, at that location is, according to Eq. (1), λL=λ0−DΔx. Since the left marginal ray40L is at the reference wavelength λ0, the left marginal ray40L will be attenuated depending on a selected and predetermined bandwidth of the passband41A of the upstream SVF35A; for sake of this example, e.g. a 10 dB bandwidth is taken to be 2DΔx. Thus, the left marginal ray40L will be attenuated by the predetermined attenuation, e.g. 10 dB. Similarly, the right marginal ray40R strikes the upstream SVF35A at a location λ0+Δx. Transmission wavelength λRat that location is, according to Eq. (1), λR=λ0+DΔx. The right marginal ray40R will also be attenuated by the predetermined attenuation, e.g. 10 dB. All rays at the reference wavelength λ0within the acceptance angle39will be attenuated by a value smaller than the predetermined level, e.g. 10 dB; and all rays at the reference wavelength λ0outside the acceptance angle39will be attenuated by a value larger than the predetermined level, e.g. 10 dB, thereby greatly reducing the amount of light, at incident angles greater than the acceptance angel39, from being transmitted to the downstream SVF35B, thereby eliminated the need for bulky collimating lenses and optics. The upstream SVF35A functions as spatial filter, effectively limiting the numerical aperture (NA) of incoming light to be separated in individual wavelengths by the downstream SVF35B. This results in reduction of the dependence of spectral selectivity of the SVF7in comparison with the corresponding dependence of the spectral selectivity of the single downstream SVF35B on the degree of collimation of the optical beam37. The term “spectral selectivity” may include such parameters as passband width, stray light rejection, extinction ratio, etc.

The center wavelengths λTof the upstream35A and downstream35B SVF may be monotonically increasing or decreasing in the first direction38. The dependence of the bandpass center wavelength λTon the x-coordinate along the first direction38of the upstream SVF35A and downstream35B SVF may be identical, or different to enable adjustment of the acceptance angle and/or wavelength response of the optical filter7. In one embodiment, the bandpass center wavelengths λTof the upstream SVF35A and downstream SVF35B are aligned with each other, such that a line connecting positions corresponding to a same bandpass center wavelength λTof the upstream SVF35A and the downstream SVF35B forms an angle of less than a predetermined amount, e.g., 30°, with the normal36to the downstream SVF35B. For non-zero angles with the normal36, the acceptance cone39may appear tilted. Thus, it is possible to vary the acceptance cone39direction by offsetting the upstream SVF35A and the downstream SVF35B relative to each other in the first direction38. For a better overall throughput, a lateral distance Δx1along the first direction38, corresponding to a bandwidth of the upstream SVF35A, may be larger than a corresponding lateral distance Δx2along the first direction38, corresponding to a bandwidth of the downstream SVF35B. In one example implementation, the upstream SVF35A and the downstream35B SVF each have a 3 dB passband no greater than 10% of a corresponding wavelength range of the upstream SVF35A and the downstream SVF35B.

Referring toFIG. 6, the spectrometer15includes the optical filter7and a photodetector array8disposed in the optical path downstream of the downstream SVF35B. The photodetector array8may include pixels44disposed along the first direction38and optionally along a second perpendicular direction (into the page) for detecting optical power levels of individual spectral components of the optical beam, e.g., reflected by the flowing material from the light source6. In an example implementation, the photodetector array may be the 2D photodetector array disclosed in U.S. patent application Ser. No. 14/818,986, entitled “OPTICAL FILTER AND SPECTROMETER” by Smith et al, filed Aug. 5, 2015, which is incorporated herein by reference. Accordingly, the optical beam may be converging, diverging, collimated, etc. As explained above, the dual-filter structure of the optical filter7, including the upstream SVF35A and the downstream SVF35B results in lessening the dependence of spectral selectivity of the optical filter7on a degree of collimation of the returning light.

In one example implementation, the photodetector array8may be in direct contact with the downstream SVF35B. The photodetector array8may be flooded with a potting material so as to form an encapsulation45. One function of the encapsulation45is to insulate the photodetector array8, while not obscuring a clear aperture46of the downstream SVF35B of the optical filter7. Another function of the encapsulation45is to protect edges of the upstream35A and downstream35B filters from impact, moisture, etc.

Applications

FIGS. 7aand 7bare diagrams of side and end views, respectively, of a V-shaped mixing vessel for use with the probes1. With reference toFIGS. 7aand 7b, a plurality of the probes1may be used in a monitoring system for a batch processing system, e.g., in the pharmaceutical industry. A processing tank51includes a support frame52for supporting a mixing vessel, such as V-shaped mixing vessel53. The mixing vessel53includes at least one input port54for inputting the raw ingredients, and at least one output port55for discharging the finished product. An agitator or chopper56may be provided inside the mixing vessel53to reduce the size of the raw ingredients and/or mix the various raw ingredients together. The agitator56may be rotated using a sprocket and chain structure57, or some other suitable driving assembly, which is driven by a motor58. A control system59may be provided for controlling the input of the ingredients, the activation and speed of the agitator56, as well as the timing of the discharge of the finished product via output port55. The control system59may be controlled automatically according to pre-set programming stored on non-transitory memory actuated by a computer controller or may require human intervention at selected times.

One or more probes1may be placed in with the raw ingredients, or even separately with different raw ingredients that are input through separate input ports54, and follow along with the raw ingredients as they mix with each other and/or react with each other due to their chemical properties or other external factors, such as a change in temperature or pressure, or the addition of a catalyst. Throughout the process, the probes1, via the controller12and the communication module21may continually transmit spectrum data to the control system59(base station), e.g., wirelessly via WIFI, at predetermined time intervals to provide constant status updates of the chemical process. The control system59and/or the controller12may utilize the spectrum data and any other test data collected by the other sensors14in one of many different ways. In one example implementation, the control system59and/or the controller12may utilize the spectrum and test data to determine when the process is complete, i.e. to shut the process off, and output the finished product. In addition, the control system59and/or the controller12may utilize the spectrum and test data to adjust the frequency or speed of the agitator56and/or to adjust the parameters of the chemical process, e.g. adjust any one or more of the temperature, the pressure, and the amount of catalyst. For multi-step processes, the control system59and/or the controller12may utilize the spectrum and test data to initiate subsequent steps in the process, e.g. as the spectrum and test data reach desired output levels. The control system59and/or the controller12may even distribute additional catalysts or ingredients at specific times based on the spectrum and test data from the storage compartment10via hatch9.

The control system59and/or the controller12may identify the position of the various probes1using each probe's positioning system, e.g., GPS, and may prioritize which probe1has greater significance in determining a next step based on the position of that probe1. In addition, since each probe1may have a plurality of spectrometers15, the control system59and/or the controller12may average the spectrum data for each probe1. The averaging process may include eliminating high and low measurements or any measurement outside a predetermined deviation from the average of the remaining measurements. Averaging may include averaging the different spectra from the different windows4/spectrometers15within each probe1, and/or average the spectra from multiple probes1at multiple locations throughout the volume of flowing material. The controller12or the control system59may also include suitable programming to perform other spectrum processing including differencing similar or different spectra regions to compare readings or combining different overlapping or adjacent spectra to generate a wider spectrum.

The position of each probe1may be adjusted by utilizing the onboard propulsion system33, the onboard buoyancy system31, or by using a process propulsion system external to each probe1, such as an electro-magnet60energized at a predetermined or desired location to attract one or more of the probes1in a required direction or into a desired zone of the vessel53. In this system, the probes1can easily be collected for re-use when the finished product is output the outlet port55.

With reference toFIG. 8, the probes1may be used in a continuous process including a settling tank61. The settling tank61includes an input port62for inputting raw or unprocessed ingredients proximate the middle of the tank61, and an agitator or rake63, which is mounted on the end of rotating shaft64, and rotates around the bottom of the settling tank61. An output port65is provided in the bottom of the settling tank61for outputting processed material, e.g. thickened liquid. An overflow channel66is provided around the top of the settling tank61to capture all the lighter fluid and materials, which rise to the top of the settling tank61.

One or more probes1may be placed in with the raw ingredients through input port62, and follow along with the raw ingredients as they mix with each other and/or react with each other due to their chemical properties or other external factors, such as a change in temperature or pressure, or the addition of a catalyst. Throughout the process, the controllers12may continually transmit spectrum data, e.g., wirelessly via WIFI, to a base station69at predetermined time intervals to provide constant status updates of the chemical process. The base station69and/or the controllers12may utilize the spectrum data and any other test data collected by the other sensors14in one of many different ways. For example, the base station69and/or the controllers12may simply utilize the spectrum and test data to determine when the process has reached a certain stage, i.e., outputs the finished product via the output port65. In addition, the base station69and/or the controllers12may utilize the spectrum and test data to adjust the frequency or speed of the rake64and/or to adjust the parameters of the chemical process, e.g. adjust any one or more of the temperature, the pressure, and the amount of catalyst. For multi-step processes, the base station69and/or the controllers12may utilize the spectrum and test data to initiate subsequent steps in the process, e.g., as the spectrum and test data reach desired output levels. The controllers12and/or the base station69may even distribute additional catalyst or ingredients at specific times based on the spectrum and test data from the storage compartment10via hatch9.

The base station69and/or the controllers12may identify the position of the various probes1using each probes positioning system, e.g., GPS, and may prioritize which probe1has greater significance in determining a next step based on the position. In addition, since each probe1may have a plurality of spectrometers15, the base station69and/or the controllers12may average the spectrum data for each probe1. The averaging process may include eliminating high and low measurements or any measurement outside a predetermined deviation from the average of the remaining measurements.

The position of each probe1may be adjusted by the controllers12and/or the base station69utilizing the onboard propulsion system33, the onboard buoyancy system31or by using a process propulsion system external to each probe1, such as an electro-magnet68energized at a predetermined or desired location to attract one or more of the probes1in a required direction or into a desired zone of the settling tank61. In this system, the probes1may have different buoyancy properties, e.g. one for settling to the bottom for output the output port65and one for rising to the top for output the overflow channel66. Accordingly, the probes1can easily be collected for re-use when the finished product is output the various ports65and66.

With reference toFIG. 9, a multi-step process, such as a brewing process, may include several steps, e.g. lautering, boiling, fermenting, conditioning, filtering, and packaging, which may require precision monitoring provided by a monitoring system including a base station70and a plurality of probes1communicating via a wireless network, e.g., WIFI. The probes1may be inserted into each processing tank at each step or the probes1may travel with the ingredients through various steps and processing vessels.

Malting is the process where barley grain71is made ready for brewing. When malting is complete, the grains71are milled or crushed in a mill72to break apart the kernels and expose the cotyledon, which contains the majority of the carbohydrates and sugars.

Mashing converts the starches released during the malting stage into sugars that can be fermented. The milled grain is mixed with hot water in a large vessel known as a mash tun73. In this vessel, the grain and water are mixed together to create a cereal mash. During the mash, naturally occurring enzymes present in the malt convert the starches (long chain carbohydrates) in the grain into smaller molecules or simple sugars (mono-, di-, and tri-saccharides). This “conversion” is called saccharification. The result of the mashing process is a sugar rich liquid or “wort”, which is then strained through the bottom of the mash tun73or in a separate tank74in a process known as lautering. The probes1may be deposited into the mash tun73to monitor the concentration of enzymes and the concentration of starches in the wort. Prior to lautering, the mash temperature may be raised to about 75-78° C. (167-172° F.) (known as a mashout) to deactivate enzymes. Probes1may be used near the bottom of the mash tun73or lautering tank74to ensure the temperature is within the desired range throughout the container using a temperature sensor14, and to ensure the concentration of enzymes is reduced to a desired or acceptable level using one of the probe spectrometers. Additional water may be sprinkled on the grains to extract additional sugars in a process known as sparging.

The wort is moved into a large tank75known as a “copper” or kettle where it is boiled with hops and sometimes other ingredients76, such as herbs or sugars. This stage is where many chemical and technical reactions take place, and where important decisions about the flavor, color, and aroma of the beer are made. The boiling process serves to terminate enzymatic processes, precipitate proteins, isomerize hop resins, and concentrate and sterilize the wort. Hops add flavor, aroma and bitterness to the beer. The spectrum signals from the probes1may be used to determine the concentrations of the various elements and the color of the wort At the end of the boil, the hopped wort settles to clarify in a vessel called a “whirlpool”77, where the more solid particles in the wort are separated out.

After the whirlpool77, the wort is rapidly cooled via a heat exchanger78to a temperature where yeast can be added. The heat exchanger78is comprised of tubing inside a tub of cold water. It is very important to quickly cool the wort to a level where yeast can be added safely as yeast is unable to grow in high temperatures. Accordingly, temperature sensors14on the probes1may quickly determine when the wort has cooled to the required temperature evenly throughout the heat exchanger78. After the wort goes through the heat exchanger78, the cooled wort goes into a fermentation tank79. A type of yeast is selected and added, or “pitched”, to the fermentation tank79. When the yeast is added to the wort, the fermenting process begins, where the sugars turn into alcohol, carbon dioxide and other components. In the fermentation tank79, the probes1provide spectral signals relating to the concentration of those elements. When the fermentation is complete the brewer may rack the beer into a new tank, called a conditioning tank80. Conditioning of the beer is the process in which the beer ages, the flavor becomes smoother, and flavors that are unwanted dissipate. Here the spectrum signals from the probes1provide a clear indication of when the beer has reached its optimum condition, as well as the monitoring of other characteristics, such as pH. After conditioning for a week to several months, the beer may be filtered using a filter81and force carbonated for bottling, or fined in the cask.

The probes1may also be used in a much larger monitoring system, such as in active rivers, lakes, oceans and other waterways to monitor the concentration of various elements, such as pollutants, e.g. oil spills, along with other contributing factors, for example temperature and pH. The combination of the location and time of detection, and the type(s) of the pollutant detected, may enable determination of the source of pollution, as well as the resultant damage, e.g. changes in water characteristics, downstream.

As the size of the probes1decrease, they may also be used for monitoring humans or other animals in-vivo. In particular, a probe1may be ingested and the spectral data may be transmitted to a doctor's base station as the probe1traverses the patient's digestive system to monitor content, pH, temperature and various other characteristics.

In an example implementation, the probes1may be dropped from some form of flying machine, e.g., airplane, balloon, helicopter or spacecraft, to monitor various atmospheric characteristics, e.g., ozone, allergens, pollutants.

The present disclosure is not to be limited in scope by the specific example implementations described herein. Indeed, other implementations and modifications, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other implementation and modifications are intended to fall within the scope of the present disclosure. Further, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein.