System and method for measuring component concentration

Abstract

1. A method for measuring a concentration of an element in a sample, the method comprising: passing light through the sample from a first light source to a first light sensor; measuring a first light intensity of the light received at the first light sensor; passing light through the sample from a second light source to a second light sensor at the first light intensity; measuring a second light intensity of the light received at the second light sensor; determining a level of adsorption based on a difference between the intensity of light emitted from the first light source and the second light intensity; and calculating a concentration of the element in the sample based on the level of adsorption and the total optical path length of the light traversed between the first light source and light sensor and the second light source and light sensor.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority from U.S. Patent Application No. 63 / 123,167, filed on December 9, 2020, entitled "Optical Sensing", the entire content of which is incorporated herein by reference.

[0002] This disclosure relates to the measurement of mixture concentration by optical adsorption.

Background Art

[0003] There are many methods used for the analysis of gas and liquid compositions, including gas and liquid chromatography - mass spectrometry. Chromatographic methods based on the differences in the adsorption of various mixtures offer advantages, including the ability to detect low concentrations in gas and liquid mixtures with high selectivity. Mass spectrometry uses a mass spectrometer to identify the particles present in a substance. The particles are ionized and pass through an electromagnetic field. The way the particles are deflected indicates their mass and thus their identity. Both chromatography and mass spectrometry are accurate methods but require the use of expensive and complex equipment. Also, those methods are relatively slow and thus not suitable for real - time analysis of compositions. For example, such methods are not practical for real - time analysis of exhaled breath in medical applications.

[0004] Electrochemical-based analytical systems utilize electrochemical gas sensors in which a gas from a sample diffuses through a semipermeable barrier, such as a membrane, then into an electrolyte solution, and then typically to one of three electrodes. At one of the three electrodes, detection of a redox reaction occurs. At a second counter electrode, a complementary, reverse redox reaction occurs. A third electrode is typically provided as a reference electrode. During oxidation or reduction of a mixed component (e.g., nitrogen oxide) at the detection electrode, a current between the detection electrode and the counter electrode can be measured, proportional to the amount of substance reacting at the detection electrode surface. The reference electrode is used to maintain a constant voltage at the detection electrode. While electrochemical-based instruments offer high sensitivity and accuracy, they require frequent calibration and inspection. Furthermore, this method has selectivity issues for low concentrations of the measurement mixture.

[0005] Most simple and reliable gas analysis methods involve the direct optical measurement of gas components by the adsorption of light of various wavelengths. The main advantage of this method is the stability of adsorption over time, due to the adsorption coefficient being a fundamental constant. Therefore, such gas analyzers do not require frequent calibration and provide stable measurements as long as the optical system is kept clean. A current gas analyzer 10 based on photoadsorption (see Figure 1) consists of a light source 20 that generates radiation of wavelengths adsorbed by the gas component to be measured, an optical cuvette 25 that passes light through the contained gas and has a sealing 26 and an optical window 27 at each end, a gas input 30, a gas output 40, and a photosensor 50 supplied by a lens 55 that can convert the light from the light source 20 that has passed through the gas into a voltage signal. Suitable light sources 20 include LEDs and laser diodes, and suitable photosensors 50 include photodiodes, photoresistors, or phototransistors, which have virtually unlimited service life and sufficiently stable characteristics. [Overview of the project]

[0006] Therefore, a primary objective of the present invention is to overcome at least some of the shortcomings of prior art plasma generation systems. This is provided in one embodiment by a system for measuring component concentrations in a sample, the system comprising: a container for containing the sample; a first light source arranged to emit light through the sample in the container; a first photosensor arranged to receive light from the first light source that has passed through the sample in the container; a second light source arranged to emit light through the sample in the container; a second photosensor arranged to receive light from the second light source that has passed through the sample in the container; and a control circuit communicating with the first photosensor and the second light source and photosensor, configured to receive a light intensity measurement from the first photosensor, cause the second light source to emit light based on the received light intensity, receive light intensity from the second photosensor, determine an adsorption level based on the difference in intensity between the light emitted from the first light source and the light received by the second photosensor, and calculate the component concentration in the sample based on the adsorption level and the total optical path length of the light that has passed between the first light source and photosensor and the second light source and photosensor.

[0007] In one embodiment, the system further comprises one or more additional light sources and photosensors, and the control circuit is configured to emit light from each sequential light source based on the intensity measured by each preceding photosensor, determine the adsorption level based on the difference in intensity between the light emitted from the first light source and the light received by the last photosensor, and calculate the component concentration in the sample based on the adsorption level and the total optical path length of the light that has passed between each light source and photosensor.

[0008] In another embodiment, one or more of the first or second sensors or light sources are in contact with the sample inside the container.

[0009] In one embodiment, the container comprises one or more transparent portions, and one or more first or second sensors or light sources are positioned outside the container to direct or receive light through the one or more transparent portions.

[0010] In another embodiment, the container includes an inlet and an outlet for allowing the sample to enter and exit the container.

[0011] In one embodiment, the component concentration is the concentration of NO2.

[0012] In another embodiment, the first light source emits light with a wavelength of approximately 350 nm to approximately 400 nm.

[0013] In one embodiment, the first light source comprises one or more light-emitting diodes or laser diodes.

[0014] In another embodiment, the first light sensor comprises one or more photodiodes, photoresistors, or phototransistors.

[0015] In one embodiment, the light emitted from the second light source has an intensity equal to the received light intensity.

[0016] In another embodiment, the light emitted from the second light source has a higher intensity than the received light intensity.

[0017] In one embodiment, the light emitted from the second light source has a weaker intensity than the received light intensity.

[0018] In one independent embodiment, a method is provided for measuring the concentration of a component in a sample, the method comprising: passing light through the sample from a first light source to a first photosensor; measuring a first light intensity of the light received by the first photosensor; passing light through the sample from a second light source to a second photosensor at the first light intensity; measuring a second light intensity of the light received by the second photosensor; determining an adsorption level based on the difference between the light intensity emitted from the first light source and the second light intensity; and calculating the concentration of a component in the sample based on the adsorption level and the total optical path length of the light that has passed between the first light source and photosensor and the second light source and photosensor.

[0019] In one embodiment, the method further includes emitting light from each of one or more sequential light sources based on the intensity measured at each of one or more preceding optical sensors, determining an adsorption level based on the difference in intensity from the light emitted from the first light source and the light received at the last optical sensor, and calculating a component concentration in the sample based on the adsorption level and the total optical path length of the light passing between each light source and optical sensor.

[0020] In another embodiment, one or more of the first or second sensors or light sources are in contact with the sample within a container.

[0021] In one embodiment, the sample is within a container having one or more transparent portions, and one or more of the first or second sensors or light sources are disposed outside the container to direct or receive light through the one or more transparent portions.

[0022] In another embodiment, the container includes an inlet and an outlet, and the method further includes passing the sample into and out of the container through the inlet and outlet.

[0023] In one embodiment, the component concentration is the concentration of NO2.

[0024] In another embodiment, the first light source emits light having a wavelength from about 350 nm to about 400 nm.

[0025] In one embodiment, the first light source includes one or more light-emitting diodes or laser diodes.

[0026] In another embodiment, the first optical sensor includes one or more photodiodes, photoreistors, or phototransistors.

[0027] In one embodiment, the light emitted from the second light source has an intensity equal to the received light intensity.

[0028] In another embodiment, the light emitted from the second light source has an intensity greater than the received light intensity.

[0029] In one embodiment, the light emitted from the second light source has an intensity weaker than the received light intensity.

[0030] Further features and advantages of the present invention will become apparent from the following drawings and description.

[0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the patent specification, including definitions, will control. As used herein, the articles “a” and “an” mean “at least one” or “one or more” unless the context clearly dictates otherwise. As used herein, “and / or” means any one or more of the items in the list connected by “and / or”. By way of example, “x and / or y” means any element of the set of three elements {(x), (y), (x, y)}. In other words, “x and / or y” means “x, y, or both x and y”. As another example, “x, y, and / or z” means any element of the set of seven elements {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}.

[0032] Furthermore, unless explicitly stated to the contrary, “or” refers to an inclusive or and not an exclusive or. For example, the condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), as well as both A and B are true (or present).

[0033] Furthermore, the use of “one (a)” or “one (an)” is used to describe the elements and components of embodiments of the concept of the present invention. This is done simply for convenience to give a general understanding of the concept of the invention, and “one (a)” and “one (an)” are intended to include one or at least one, and the singular form also includes the plural form unless it is clear that it means the other.

[0034] As used herein, the term “about” is intended to include a variation of ±10%, more preferably ±5%, even more preferably ±1%, and even more preferably ±0.1% from a specified value when referring to a measurable value such as a quantity or duration, such variation is appropriate for performing the disclosed apparatus and / or method.

[0035] The following embodiments and aspects are described and explained in relation to systems, tools, and methods, and are intended to be exemplary and illustrative, but not limiting in scope. In various embodiments, one or more of the above problems are reduced or eliminated, while other embodiments are directed toward other advantages or improvements.

[0036] To better understand the present invention and to show how the same can be carried out, Next, referring to the attached drawing as merely an example, similar reference numerals throughout the drawing indicate corresponding sections or elements.

[0037] Herein, with particular close reference to the drawings, it is emphasized that the details shown are merely examples, intended to illustrate preferred embodiments of the invention, and are presented to provide what is considered to be the most useful and understandable explanation of the principles and conceptual aspects of the invention. In this regard, no attempt has been made to show structural details of the invention in more detail than is necessary for a basic understanding of the invention, and the explanations presented with the drawings will make it clear to those skilled in the art how some forms of the invention can actually be embodied. The accompanying drawings are as follows: [Brief explanation of the drawing]

[0038] [Figure 1] This shows a light-adsorption-based concentration sensor based on prior art. [Figure 2A-2B] An exemplary sensor with parallel mirrors for increasing the beam path length, based on prior art, is shown. [Figure 3] The present disclosure describes exemplary photo-adsorption-based sensors that use a series of sequential photosensors and light sources to electronically increase the beam path length, according to several embodiments of this disclosure. [Figure 4] The proportional relationship between measured and emitted light intensity is shown in some embodiments of this disclosure. [Figure 5] Some embodiments of this disclosure demonstrate a relationship stronger than proportionality between measured and emitted light intensities. [Figure 6] Some embodiments of this disclosure demonstrate a relationship weaker than proportionality between measured and emitted light intensities. [Figure 7] The present disclosure illustrates exemplary circuits for relating measured and emitted light according to several embodiments of this disclosure. [Modes for carrying out the invention]

[0039] Before describing at least one embodiment in detail, it should be understood that the present invention is not limited in its applications to the details of the configuration and arrangement of components described below or shown in the drawings. The present invention is applicable to other embodiments that are carried out or performed in various ways. It should also be understood that the expressions and terminology used herein are for illustrative purposes only and should not be considered limiting.

[0040] One potential drawback of photoadsorption systems, such as system 10 in Figure 1, lies in measuring low concentrations. This drawback can be addressed by increasing the optical path length of the light passing through the gas. Because the light passes through a large amount of the test gas, adsorption can be increased to an amount that is easily measurable even at low concentrations. Increasing the optical path length can be achieved by increasing the size of the optical cuvette containing the test gas and through which the light passes. However, increasing the size of the optical cuvette can lead to packaging problems. The optical path length can also be increased by using mirrors to reflect the light passing through the test gas multiple times without increasing the size of the optical cuvette (see Figures 2A-2B).

[0041] Figure 2A shows a cross-sectional view of the multi-pass optical cuvette system 100, and Figure 2B shows a perspective view of the cuvette 100. The cuvette system 100 comprises a pair of mirrors 110 facing each other, a light source 120 which is optionally a laser, a laser adjustment system 130, a beam input channel 140, a beam output channel 150, a seal 160, and an optical sensor 170. The laser beam 180 enters through the beam input channel 140 and is reflected multiple times between the mirrors 110 until it exits through the beam output channel 150, and is measured by the optical sensor 170. While the mirrors 110 can be used to increase sensitivity to low densities by several times, the optical path length and sensitivity of such a cuvette system 100 are limited by the divergence of the laser beam. Natural beam divergence and accumulation of errors during continuous beam reflection limit the maximum optical path length that can be achieved with such a device.

[0042] The systems and methods of the present disclosure address the drawbacks of electronic mirrors by providing one or more electronic mirrors comprising optical sensors and light source units. Each optical sensor can receive light from a preceding light source in the chain, measure its intensity, and then re-emit light from the coupled light source at its measured intensity. The process can be repeated as many times as necessary to achieve a desired optical path length, and cumulative adsorption can be measured as the total intensity drop from the first light source in the chain to the last optical sensor in the chain.

[0043] A chain of light sources and light sensors can be coupled through electronic circuits so that each sequential light source emits light at an intensity proportional to, greater than, or less than proportional to the intensity of light received by a preceding light sensor. The light sensors and light sources can be directly coupled and controlled by a basic circuit, or they can communicate with a computing system comprising a processor and memory, configured to receive various intensity measurements from the light sensors and direct proportional emission from the various light sources.

[0044] Aspects of the present disclosure may include a system for measuring the concentration of components in a sample. Such a system may include a container for containing the sample, a first light source positioned to emit light through the sample in the container, a first photosensor positioned to receive light from the first light source that has passed through the sample in the container, a second light source positioned to emit light through the sample in the container, a second photosensor positioned to receive light from the second light source that has passed through the sample in the container, and a processor or control circuit communicating with the first photosensor and the second light source and photosensor. The processor or control circuit may be configured to receive a light intensity measurement from the first photosensor, cause the second light source to emit light based on the received light intensity, receive a light intensity from the second photosensor, determine an adsorption level based on the difference in intensity between the light emitted from the first light source and the light received by the second photosensor, and calculate the concentration of components in the sample based on the adsorption level and the total optical path length of the light that has passed between the first light source and photosensor and the second light source and photosensor.

[0045] As used herein, the term “control circuit” includes, but is not limited to, any suitable circuit, such as a processor.

[0046] In one embodiment, the system may further include one or more additional light sources and photosensors, and the processor is configured to emit light from each sequential light source based on the intensity measured by each preceding photosensor, determine the adsorption level based on the difference in intensity between the light emitted from the first light source and the light received by the last photosensor, and calculate the component concentration in the sample based on the adsorption level and the total optical path length of the light that has passed between each light source and photosensor.

[0047] One or more of the first or second sensors or light sources may be positioned inside the container in contact with the sample. In one embodiment, the container may have one or more transparent sections, and one or more of the first or second sensors or light sources may be positioned outside the container to direct or receive light through one or more transparent sections. The container may include an inlet and an outlet for the sample to enter and exit the container. The component concentration may be the concentration of nitrogen dioxide (NO2). The first light source may emit light with wavelengths of about 350 nm to about 400 nm.

[0048] In various embodiments, the first light source may comprise one or more light-emitting diodes or laser diodes. The first light sensor may comprise one or more photodiodes, photoresistors, or phototransistors. The light emitted from the second light source may have an intensity equal to, greater than, or less than the received light intensity.

[0049] Aspects of the present disclosure may include a method for measuring the concentration of a component in a sample. Such a method may include passing light through the sample from a first light source to a first photosensor, measuring a first light intensity of the light received by the first photosensor, passing light through the sample from a second light source to a second photosensor at the first light intensity, measuring a second light intensity of the light received by the second photosensor, determining an adsorption level based on the difference between the light intensity emitted from the first light source and the second light intensity, and calculating the concentration of a component in the sample based on the adsorption level and the total optical path length of the light that has passed between the first light source and photosensor and the second light source and photosensor.

[0050] In one embodiment, the method may further include emitting light from each of one or more consecutive light sources based on the intensity measured by each of one or more preceding photosensors; determining the adsorption level based on the difference in intensity between the light emitted from the first light source and the light received by the last photosensor; and calculating the component concentration in the sample based on the adsorption level and the total optical path length of the light that has passed between each light source and photosensor.

[0051] The systems and methods of this disclosure relate to the measurement of sample component concentrations by photoadsorption. As stated, direct optical measurement of gas components by adsorption of light of a certain wavelength provides a simple and reliable gas analysis for a variety of applications, including many in the medical and industrial fields. The main advantage of such methods is the stability of adsorption over time, due to the adsorption coefficient being essentially constant; however, such methods are limited in their ability to detect low concentrations, particularly when spatial constraints limit the beam path length through the sample. Physical beam manipulation (e.g., using mirrors) to increase the path length faces drawbacks associated with beam divergence.

[0052] The systems and methods of the present disclosure address the aforementioned shortcomings by providing a multiple-pass sensor that relies on a series of connected photosensors and light sources to pass light through a sample multiple times (thus substantially extending the optical path length) while measuring the cumulative decrease in intensity that determines adsorption. The wavelength of the emitted light may be selected as one that is adsorbed by the target gas component, and the photosensors may measure the light intensity after the emitted light has passed through the gas. Thus, the adsorbed and associated gas component concentrations can be determined. The light source may include readily available LEDs or laser diodes, and the photosensors may be selected from photodiodes, photoresistors, or phototransistors, all of which have virtually unlimited lifetimes and stable characteristics.

[0053] An exemplary system 200 of the present disclosure is shown in Figure 3. A series of electronically coupled light sensors 210 and light sources 220 are arranged on both sides of a container 230 containing a sample. In one embodiment, each light sensor 210 is implemented as a phototransistor (PT). In another embodiment, each light source 220 is implemented as one or more light-emitting diodes (LEDs). A series of transparent windows 240 allow light to enter and exit the container 230 between the consecutive light sources 220 and sensors 210. In one embodiment, the system 200 further includes a plurality of cuvettes 250, each positioned between a pair of transparent windows 240, with the pair of transparent windows 240 positioned on opposite sides of the container 230. Although the system 200 is shown to include a plurality of cuvettes 250, this is not intended to limit it in any way, and the system 200 can operate similarly without cuvettes 250. In one embodiment (not shown for brevity), the container 230 has an inlet and an outlet, as described above in relation to the cuvette system 100 and analyzer 10.

[0054] In one embodiment, the output of each sensor 210 controls the input of each light source 220. In one example, the emitter of each sensor 210 is coupled to the base of each transistor 260, and the emitter of each transistor 260 is coupled to the anode of each light source 220. In one embodiment, the output of the last sensor 210 is coupled to the input of an analog-to-digital converter (ADC) via a register 270.

[0055] The systems and methods of this disclosure are particularly useful for measuring sample components having concentrations in the ppb range with fast response times. Similar to regular multiple pass cuvettes (e.g., the mirror embodiment shown in Figures 2A-2B), an increase in optical path length is achieved, but instead of physically folding the light beam multiple times within a small container, the systems and methods of this disclosure can use continuous re-emission of light by LEDs placed at the beginning of each separate cuvette.

[0056] In some embodiments, the light intensity of each light source 220 is proportional to the light intensity of the sensor 210 or cuvette before it is driven by a current amplification circuit using a transistor or other current amplifier. Thus, all cuvettes 250 function as a single cuvette with an arbitrary optical path length determined by the amount of continuous cuvettes 250 that can be made as long as needed while still allowing for small packaging. The systems and methods of this disclosure do not require complex and precise optical servicing and adjustment procedures. Such cuvettes 250 function as regular optical cuvettes (requiring simple routine cleaning and maintenance) but have virtually unlimited optical path lengths.

[0057] In some embodiments, the light intensity of each light source 220 may not be directly proportional to the light intensity of the preceding sensor or cuvette, and may have a stronger-than-proportional relationship. This relationship could be, for example, an exponential dependence, as shown in Figure 4, or a linear dependence starting from a non-zero point on the x-axis, or another stronger dependence. The relationship between the consecutive light sensors 210 and light sources 220 can be governed by a simple electronic circuit or a computer system following a programmed algorithm. Current amplification with a stronger-than-proportional dependence allows for improved sensitivity, but the dynamic range of the measured concentration becomes narrower.

[0058] In some embodiments, the light intensity of each light source 220 may not be directly proportional to the light intensity of the preceding cuvette or sensor, and may have a weaker-than-proportional relationship. This relationship may be, for example, a curvilinear dependence (shown by curve 280), a linear dependence starting from a non-zero point on the x-axis (shown by line 281), or another weaker dependence, as shown in Figure 5. Alternatively, the light intensity of each light source 220 may have a stronger-than-proportional relationship, such as a logarithmic dependence (shown by curve 282), or a linear dependence starting from a non-zero point on the y-axis (shown by line 283), as shown in Figure 6.

[0059] The relationship can be governed by a current amplification circuit using a transistor or other current amplifier, for example, as shown in Figure 7. Specifically, Figure 7 shows an amplification circuit 300 comprising a Zener diode 310, a resistor 320, a bipolar junction transistor 330, and a resistor 340. The anode of the Zener diode 310 is coupled to a common potential, and the cathode of the Zener diode 310 is coupled to the first end of the resistor 320. The second end of the resistor 320 is coupled to the base of the transistor 330 and the emitter of the phototransistor 210. The collector of the transistor 330 is coupled to the cathode of the LED 220, and the emitter of the transistor 330 is coupled to a common potential via the resistor 340. In one embodiment, the resistor 320 is an adjustable resistor, and the control terminal of the resistor 320 is coupled to the emitter of the PD 210. Thus, the dependence responds to the Zener voltage of the Zener diode 310. Specifically, whether the Zener voltage is equal to, lower than, or higher than the base-emitter voltage of transistor 330 will determine the dependence between LED 220 and PD 210.

[0060] Current amplification with a weaker-than-proportional dependence offers reduced sensitivity but a wider dynamic range of the measured concentration. Exemplary sensitivities and ranges of various approaches are discussed in the following examples.

[0061] Examples: Example 1: Air Ozone Analyzer Gas flow rate: 4-40 liters / hour A 4m optical path length multi-path optical cuvette consisting of eight 0.5m sections, using a series of directly proportionally coupled sensors and light sources. Light source LED wavelength: 265nm Measurement range: 10 ppb to 2 ppm

[0062] Example 2: Air Ozone Analyzer Water flow rate: 0.4~4l / hour A 4m optical path length multi-path optical cuvette consisting of eight 0.5m sections, using a series of directly proportionally coupled sensors and light sources. LED wavelength: 265nm Measurement range: 10ppb~2ppm

[0063] Example 3: Air Ozone Analyzer Gas flow rate: 4-40 liters / hour A 4m optical path length multi-path optical cuvette consisting of eight 0.5m sections, using a series of sensors and light sources that are more strongly coupled than proportionally. LED wavelength: 265nm Measurement range: 1ppb~50ppb

[0064] Example 4: Air Ozone Analyzer Gas flow rate: 4-40 liters / hour A 4m optical path length multi-path optical cuvette consisting of eight 0.5m sections, using a series of sensors and light sources that are weaker than directly proportionally coupled. LED wavelength: 265nm Measurement range: 20ppb~100ppm

[0065] Example #5: Nitrogen dioxide analyzer in air Gas flow rate: 4-40 liters / hour A 4m optical path length multi-path optical cuvette consisting of eight 0.5m sections, using a series of directly proportionally coupled sensors and light sources. LED wavelength: 405nm Measurement range: 40ppb~8ppm

[0066] As a person skilled in the art would recognize as necessary or best suited to the systems and methods of the disclosure, the systems and methods of the disclosure may include a computing unit that includes one or more processors (e.g., a central processing unit (CPU), a graphics processing unit (GPU), etc.), computer-readable storage devices (e.g., main memory, static memory, etc.), or a combination thereof communicating with each other via a bus. The computing unit may include portable devices (e.g., mobile phones), personal computers, and server computers. In various embodiments, the computing units may be configured to communicate with each other via a network.

[0067] The computing unit may be used to control the operation of valves and pumps, the processing of sensor data from NO sensors, and the systems described herein, including filter-related sensors.

[0068] The processor may include any suitable processor known in the art, such as a processor sold by Intel (Santa Clara, CA) under the trademark XEON E7, or a processor sold by AMD (Sunnyvale, CA) under the trademark OPTERON 6200.

[0069] The memory preferably includes at least one tangible non-temporary medium capable of storing one or more sets of instructions executable to cause the system to perform the functions described herein (e.g., software embodying any of the methodologies or functions found herein), data (e.g., data encoded in memory stanz), or both. While the computer-readable storage device may be a single medium in exemplary embodiments, the term “computer-readable storage device” should be interpreted to include a single or multiple mediums for storing instructions or data (e.g., centralized or distributed databases, and / or associated caches and servers). The term “computer-readable storage device” should therefore be interpreted, not limited to, solid memory (e.g., subscriber identification module (SIM) cards, secure digital cards (SD cards), microSD cards, or solid-state drives (SSDs)), optical and magnetic media, hard drives, disk drives, and any other tangible storage media.

[0070] For example, any suitable service such as Amazon Web Services, cloud storage, another server, or other computer-readable storage can be used for storage. Cloud storage may refer to a data storage scheme in which data is stored in a logical pool and physical storage may be spread across multiple servers and locations. Storage may be owned and managed by a hosting company. Preferably, storage is used to store records as needed to perform and support the operations described herein.

[0071] The input / output devices described herein may include one or more of the following: a video display unit (e.g., a liquid crystal display (LCD) or cathode ray tube (CRT) monitor), an alphanumeric input device (e.g., a keyboard), a cursor control device (e.g., a mouse or trackpad), a disk drive unit, a signal generator (e.g., a speaker), a touchscreen, buttons, an accelerometer, a microphone, a cellular radio frequency antenna, a network interface device which may be, for example, a network interface card (NIC), a Wi-Fi card, or a cellular modem, or any combination thereof. The input / output devices may be used to input desired NO concentration levels and flow rates and to alert the user regarding sensor readings and the need for filter replacement.

[0072] Those skilled in the art will recognize that any suitable development environment or programming language may be employed to enable the operability described herein for the various systems and methods of this disclosure. For example, the systems and methods herein may be implemented using C++, C#, Java, JavaScript, Visual Basic, Ruby on Rails, Groovy and Grails, or any other suitable tool. For the arithmetic unit, it may be preferable to use native Xcode or Android Java.

[0073] For clarity, it is understood that certain features of the present invention described in relation to separate embodiments may be provided in combination in a single embodiment. Conversely, various features of the present invention described in relation to a single embodiment for brevity may be provided separately or in any preferred subcombination.

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains. Methods similar to or equivalent to those described herein may be used in carrying out or testing the present invention, but preferred methods are described herein.

[0075] All documents, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of any conflict, the patent specification, including definitions, shall prevail. Furthermore, materials, methods, and examples are illustrative and not intended to be limiting.

[0076] Those skilled in the art will understand that the present invention is not limited to what is specifically shown and described above. Rather, the scope of the present invention is defined by the appended claims and includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof, which those skilled in the art will notice upon reading the foregoing description.

Claims

1. A system for measuring the concentration of components in a sample, wherein the system is A container for containing the aforementioned sample, A first light source is arranged to emit light through the sample in the container, A first photosensor is positioned to receive light from the first light source that has passed through the sample in the container, A second light source is arranged to emit light through the sample in the container, A second photosensor is positioned to receive light from the second light source that has passed through the sample in the container, A control circuit that communicates with the first light sensor, the second light source, and the second light sensor, wherein the control circuit is The light intensity measurement value is received from the first light sensor, The second light source is controlled to emit light having an intensity proportional to the received light intensity, The light intensity is received from the second light sensor, The absorption level is determined based on the difference in intensity between the light emitted from the first light source and the light received by the second light sensor. Based on the absorption level and the total optical path length of the light passing between the first light source and photosensor and the second light source and photosensor, the component concentration in the sample is calculated. A control circuit and A system equipped with these features.

2. The system further comprises an additional light source and an additional light sensor, The first light sensor, the second light sensor, the additional light sensor, the first light source, the second light source, and the additional light source are arranged as a series of electronically coupled light sensors and light sources. The aforementioned control circuit is Control each light source and each light sensor included in the series of electronically coupled light sensors and light sources to cause each continuous light source to emit light in proportion to the light intensity measured by each preceding light sensor. The absorption level is determined based on the difference in intensity between the light emitted from the first light source and the light received by the last light sensor. Based on the absorption level and the total optical path length, the component concentration in the sample is calculated. The system according to claim 1, configured as follows.

3. The system according to claim 2, wherein the container comprises one or more transparent portions, and the series of electronically coupled light sensors and light sources are arranged facing the outside of the container so as to direct or receive light through the one or more transparent portions.

4. The system according to claim 1, wherein the container is provided with an inlet and an outlet for allowing a sample to enter and exit the container.

5. The concentration of the above component is nitrogen dioxide (NO ２ The system according to claim 1, wherein the concentration is such that the first light source emits light having a wavelength of 350 nm to 400 nm.

6. The first light sensor and the second light sensor are each phototransistors, and the first light source and the second light source are each light-emitting diodes (LEDs), In the aforementioned series of electronically coupled light sensors and light sources, The aforementioned light sensor is a phototransistor, The emitter of the aforementioned phototransistor is connected to the anode of the subsequent light source. The aforementioned phototransistor performs current amplification, The system according to claim 2, wherein the light intensity of the subsequent light source is proportional to the light intensity detected by the phototransistor.

7. A method for measuring the concentration of a component in a sample, wherein the method is A step of passing light from a first light source through a sample to a first photosensor, A step of measuring the first light intensity of the light received by the first light sensor, A step of passing light from a second light source through the sample to a second photosensor, The process includes: the light emitted by the second light source having the same light intensity as the first light intensity, and the first light source and the second light source including a laser diode; A step of measuring the second light intensity of the light received by the second light sensor, A step of determining the absorption level based on the difference between the intensity of light emitted from the first light source and the second light intensity, A step of calculating the component concentration in the sample based on the absorption level and the total optical path length of the light that has passed between the first light source and photosensor and the second light source and photosensor. Methods that include...

8. The sample is contained within a container having one or more transparent portions, and the first sensor, the second sensor, the first light source, and the second light source are positioned outside the container such that they direct or receive light through the one or more transparent portions. The container is equipped with an inlet and an outlet, The method further includes allowing the sample to enter and exit the container through the inlet and outlet, The aforementioned component concentration is the concentration of nitrogen dioxide (NO₂), The first light source emits light with a wavelength of 350 nm to 400 nm. The method according to claim 7.

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