Dual detector gas detection system

Abstract

The present invention is entitled "Dual-detector gas detection system." The apparatus and related methods provided herein relate to a gas detection apparatus that includes a primary optical element configured to: (1) direct a first portion of light emitted from a light-generating element to a primary detector via a second optical element (after the first portion of light has interacted with a target medium), and (2) direct a second portion of light emitted from the light-generating element to a reference detector via a third optical element. In various examples, the primary optical element can be a reflector, such as a mirror. The light-generating element may, for example, be one or more red, green, blue (RGB) light-emitting diodes (LEDs). The optical train may, for example, have a single / monolithic molded transparent acrylic construction and internal reflective surfaces. The gas detection apparatus can standardize the optical paths used by the light-generating element and the primary detector / reference detector, thereby advantageously providing reliable operation.

Description

TECHNICAL FIELD

[0001] Various embodiments relate generally to gas detectors. BACKGROUND

[0002] Optical systems include a variety of components for generating and manipulating light. For example, an optical system can have a light generating source such as an LED or laser. The optical system can include one or more lenses for focusing and directing the generated light, and can include one or more mirrors for reflecting the generated light. The light generating source can produce visible light, infrared light, ultraviolet light, or other types / frequencies / wavelengths of light. Some light sources can emit light in a narrow frequency band, while other light sources can emit light having a wide frequency band (e.g., white light).

[0003] A gas detector is a device that detects the presence of a gas in a detection area. Gas detectors can be used to detect gas leaks or other emissions, and can interact with a control system (e.g., industrial machinery / equipment) to automatically shut down a process when a harmful gas or gas leak is detected. Gas detectors can sound an alarm to an operator in an area where a leak has occurred, which can give the operator a chance to escape a dangerous situation. Gas detectors can be used to detect flammable gases, combustible gases, and / or toxic gases, and can be used to monitor for oxygen depletion. Gas detectors can be portable, or can be integrated with fixed industrial equipment. SUMMARY

[0004] Devices and related methods relate to a gas detection device that includes a primary optical element configured to: (1) direct a first portion of light (after the first portion of light emitted from a light generating element has interacted with a target medium) to a primary detector via a second optical element, and (2) direct a second portion of light emitted from the light generating element to a reference detector via a third optical element. In various examples, the primary optical element can be a reflector such as a mirror. The light generating element may, for example, be one or more red, green, blue (RGB) light emitting diodes (LEDs). The optical system may, for example, have a single / monolithic molded transparent acrylic construction and internal reflective surfaces. The gas detection device can standardize the optical paths used by the light generating element and the primary / reference detectors, advantageously providing reliable operation.

[0005] Various embodiments can achieve one or more advantages. For example, a gas detection device can advantageously function without requiring a through-hole detector to be bent or positioned to measure off-axis reflections. Some embodiments can include a primary detector and a reference detector that can advantageously be used to reliably and accurately identify a surrounding gas. In some embodiments, a reference detector can advantageously ensure emission stability of a light generating element. A lens can provide a more focused and less dispersed beam of light to a reference detector, which can advantageously increase reliability and accuracy of the reference detector. An anti-reflective (AR) coating can advantageously avoid stray light from being detected at a primary detector and a reference detector. A pair of walls can advantageously avoid stray light from being detected at a primary detector and a reference detector. A parabolic mirror can provide a more focused and less dispersed beam of light to a reference detector, which can advantageously increase reliability and accuracy of the reference detector. A first curved reflective surface and a second curved reflective surface can provide a more focused and less dispersed beam of light to respective primary and reference detectors, which can advantageously increase reliability and accuracy of the primary and reference detectors. A waveguide can help direct light emitted from a light generating element to / from a target medium with low attenuation, thereby advantageously avoiding weakening of light signals reaching a primary detector and a reference detector. A first curved reflective surface and a second curved reflective surface can provide a more focused and less dispersed beam of light to respective primary and reference detectors, which can advantageously increase reliability and accuracy of the primary and reference detectors.

[0006] The details of various embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 A perspective view of an example gas detection device is shown coupled to a computing system.

[0008] Figure 2 A cross-sectional view of an example gas detection device is shown.

[0009] Figure 3 A cross-sectional view of an example gas detection device is shown including a parabolic mirror, an anti-reflective coating, and an optical lens.

[0010] Figure 4 A cross-sectional view of an example gas detection device is shown having an optical train including a waveguide and a pair of curved reflective surfaces.

[0011] Figure 5 A cross-sectional view of an example gas detection device is shown having an optical element including a two-part half-parabolic mirror.

[0012] Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION

[0013] Figure 1 A perspective view of an exemplary gas detection device coupled with a computing system is shown. The gas detection device 100 includes an optical train 105. A target medium 110 to be measured / detected by the gas detection device 100 is located in the vicinity of the optical train 105. The gas detection device 100 includes a light generating element 115 (e.g., one or more RGB LEDs). A primary optical element 120 (e.g., a double-sided mirror) is located above the light generating element 115. The gas detection device 100 includes a primary (photodetector) 125 and a reference (photodetector) 130.

[0014] In operation, a first portion of light emitted from the light generating element passes through or around the primary optical element, thereby illuminating the target medium. After the first portion of light interacts with the target medium (possibly changing at least one property of the first portion of light), the (altered) first portion of light is directed (e.g., reflected or re-emitted) back to the primary optical element. The primary optical element directs (e.g., reflects) the (altered) first portion of light to a secondary optical element 135 (e.g., a first reflective surface of the optical train). The secondary optical element then directs (e.g., reflects and / or focuses) the (altered) first portion of light to the primary (photodetector). In response to receiving the (altered) first portion of light, the primary detector outputs a primary signal that is used to correctly identify a chemical substance that interacted with the target medium (e.g., identify a toxic gas that changed the color of a chemical color-changing material).

[0015] In operation, a second portion of light emitted from the light generating element reaches the primary optical element. The second portion of light is directed (e.g., reflected) by the primary optical element to a tertiary optical element 140 (e.g., a second reflective surface of the optical train). The tertiary optical element then directs (e.g., reflects and / or focuses) the second portion of light to the reference (photodetector). In response to receiving the second portion of light, the reference detector outputs a reference signal that can be used to verify the correct calibration of the gas detection device 100. Thus, the signals generated by the primary (photodetector) and the reference (photodetector) can be advantageously used to reliably identify a chemical substance that interacted with the target medium.

[0016] In this example description, the gas detection system 100 includes a printed circuit board (PCB) 145. The gas detection system 100 can be, for example, fixedly coupled to the PCB. The following are operatively coupled to the gas detection system 100: a central processing unit (CPU) 150, a volatile memory (e.g., RAM) 155, and a non-volatile memory (NVM) 160. In this example embodiment, the CPU, the volatile memory, and the NVM are all fixedly coupled on the PCB. The CPU is operatively coupled to the light-generating element, the primary detector, and the reference detector, such that the CPU: (1) is configured to control the light-generating element, and (2) receives the primary signal and the reference signal from the primary detector and the reference detector, respectively. For example, the CPU can control the brightness level of the light-generating element. In various embodiments, the CPU can control the frequency of the light emitted by the light-generating element. For example, if the light-generating element is an RGB LED, the CPU can instruct the RGB LED to emit red light instead of green light or blue light.

[0017] The NVM can be used as a storage memory for the CPU. For example, the NVM can store data associated with the primary signal and the reference signal generated by the primary detector and the reference detector, respectively. The NVM can contain program instructions that can be executed by the CPU. For example, the CPU can execute an algorithm (possibly stored in the NVM) that allows the CPU to correctly identify a particular chemical (e.g., a toxic gas) based on the received primary signal and / or reference signal. The CPU can compare the received primary signal and / or reference signal for gas detection purposes. In some examples, the reference signal can be used to ensure that the light emitted from the light-generating element is constant, and that changes that can be caused by, for example, temperature, shock, and degradation are not incorrectly interpreted by the primary detector (e.g., as a false positive or a false negative).

[0018] The CPU is operatively coupled to an input / output (I / O) module 165. The I / O can transmit data from the CPU to another computing system. For example, the I / O can relay information from the CPU to a centralized database or monitoring / control system that is coupled to a plurality of distributed gas detection devices 100. The I / O can receive data from another computing system and transmit the data to the CPU. For example, a central control system can send a command to the CPU (via the I / O) instructing the CPU to stop operating / calculating due to a detected malfunction of the gas detection device 100.

[0019] In some embodiments, the optical train can be a housing that encloses a main optical element. The optical train can be, for example, a molded, unitary construction optical train. The optical train can facilitate measuring reflectivity in a gas detection system. In some examples, the gas detection system can include a light generating element, a primary detector, a reference detector, an optical feature (or reflector), and one or more detected media. In operation, a main optical element (e.g., a reflector such as a mirror) can direct a light beam emitted from the light generating element to the reference detector. The optical element can direct another light beam that has interacted with the one or more detected media to the measurement detector. The reference detector can advantageously ensure emission stability from the optical element.

[0020] Figure 2 A cross-sectional view of an example gas detection apparatus is shown. The gas detection apparatus 200 includes an optical train 205. The optical train includes two vertically extending walls 210A, 210B and two reflective surfaces 215A, 215B that are angled at 45 degrees with respect to the two vertically extending walls, respectively. The two vertically extending walls can form an upper columnar structure of the optical train. In some embodiments, the vertically extending walls can form a single wall having, for example, a cylindrical shape. In some examples, for example, the walls can include optical features such as facets or coatings that can prevent stray light from incorrectly adding noise to the gas detection apparatus. Inside the optical train is an optical element 220 (e.g., a beamsplitter).

[0021] A mirror (one example of the optical element 220) can be angled at 45 degrees with respect to the vertically extending walls and a bottom surface of the optical train such that the mirror deflects light traveling vertically in a horizontal direction. A primary detector 225, a light generating element 230, and a reference detector 235 are located below the optical train. The primary detector, the light generating element, and the reference detector are located on a top surface of a PCB 240. The gas detection apparatus 200 having the illustrated construction can advantageously function without having to bend or position through-hole detectors to measure off-axis reflections. For example, there can be assembly tolerances for optical components having leads that can be inserted into through-holes for soldering. Inserting these leads through the through-holes for soldering can result in undesirable registration and angle errors. Thus, the gas detection apparatus 200 can be constructed without such through-hole detectors and avoid such registration and angle errors associated with through-hole detectors. Instead, for example, surface mount detectors can be used as the primary detector and / or the reference detector, which can advantageously be more reliable for surface mounting compared to through-hole detectors.

[0022] When the light-generating element is turned on, light emitted from the light-generating element will travel upward toward the top of the optical element and optical train. Some of the emitted light from the light-generating element is directed by the optical element toward the right reflective surface, which will then direct the light to the reference detector. Some of the emitted light from the light-generating element travels toward the "medium to be measured" (e.g., a material that can change its spectral contribution in response to a reaction with a particular gas). When the emitted light reaches the medium to be measured, the emitted light interacts with the medium to be measured. Some of the emitted light is scattered, reflected, and / or re-emitted from the medium to be measured toward the optical element. The optical element directs such scattered or reflected light toward the left reflective surface, which directs the scattered or reflected light toward the primary detector.

[0023] In some examples, the gas detection device 200 can be referred to as a "source- reference-measurement optical train." The optical train can have a single piece of molded transparent acrylic construction (or similar material containing internal reflective surfaces). Light emitted by the light-generating element can be conducted to the medium to be measured. The first surface 220A of the optical element can act as a reflector to transmit a portion of the light to the reference detector, which can be used to ensure stability of the light-generating element. Light reflected, scattered, and / or re-emitted by the medium to be measured can impinge on the second (e.g., opposite) surface 220B of the optical element and can be reflected to the measurement (e.g., primary) detector. Thus, the optical train can facilitate the transmission of light between the medium to be measured, the light-generating element, the reference detector, and the measurement detector.

[0024] In some embodiments, an integrating lens (one example of an optical element 220) can be used to collect and focus light in the optical path of the light-generating element. The integrating lens may, for example, be used in place of a mirror. In some examples, the primary optical element can be a beamsplitter. The principles of operation of the beamsplitter can be based on the surface geometry, coatings, and / or gratings of the components. In some examples, the beamsplitter can comprise the surface(s) of the (acrylic) optical train.

[0025] Figure 3A cross-sectional view of an exemplary gas detection apparatus including a parabolic mirror, an anti-reflective coating, and an optical lens is shown. The gas detection apparatus 300 includes (e.g., similar to gas detection apparatuses 100 and 200) an optical train (with a vertical wall and first and second reflective surfaces), a light generating element (e.g., one or more LEDs), an optical element, a primary detector, and a reference detector. The gas detection apparatus 300 includes a lens 305 located between the light generating element and the optical element. The lens focuses light emitted from the light generating element toward a lens focal point (f1). The lens focal point can be adjacent to or overlap the optical element, such that the concentrated light beam reaches the optical element, is deflected toward the second reflective surface, and is deflected again toward the reference detector. In this sense, the lens can provide the reference detector with a more focused and less dispersed light beam, which can advantageously increase the reliability and accuracy of the reference detector.

[0026] The gas detection apparatus includes an anti-reflective (AR) coating 310 (e.g., magnesium fluoride) on an interior surface of the optical train between the vertical wall and the reflective surfaces of the optical train. The AR coating can advantageously avoid stray light from being detected at the primary and reference detectors. A pair of walls is located on opposite sides of the light generating element. The pair of walls 315 can be at least partially formed of an opaque material, such that the walls block light rays emitted by the light generating element. In some embodiments, the pair of walls can be acrylic and / or integrally formed with the optical train. In turn, the pair of walls (similar to the AR coating) can advantageously avoid stray light from being detected at the primary and reference detectors. In some embodiments, the AR coating can be present on other portions or surfaces of the optical train.

[0027] The target medium 110 is located on an opposite side of the optical element relative to the light generating element. In this exemplary illustration, a parabolic mirror 320 with a chemochromic coating is disposed adjacent to the target medium. The parabolic mirror is positioned to interact with and reflect light emitted by the light generating element. The parabolic mirror has a focal point (f0) that can be adjacent to, on, or overlap the optical element, such that the concentrated light beam (after interacting with the chemochromic coating of the parabolic mirror) reaches the optical element, is deflected toward the first reflective surface, and is deflected again toward the primary detector. In this sense, the parabolic mirror can provide the primary detector with a more focused and less dispersed light beam, which can advantageously increase the reliability and accuracy of the primary detector.

[0028] Figure 4A cross-sectional view of an example gas detection device having an optical train comprising a waveguide and a pair of curved reflective surfaces is shown. The gas detection device 400 comprises (e.g., similar to gas detection devices 100, 200, 300) an optical train (having a vertical wall and first and second reflective surfaces), a light generating element (e.g., one or more LEDs), an optical element, a primary detector, and a reference detector. In this example illustration, the first and second reflective surfaces 415A, 415B are curved to focus light directed by the optical element toward the respective primary and reference detectors. For example, the first and second reflective surfaces can have parabolic shapes each having their own respective focal points (e.g., f PD and f RD ).

[0029] When the light generating element is turned on, light emitted from the light generating element will travel upward toward the optical element and the top of the optical train. Some of the emitted light from the light generating element is directed by the optical element toward the second curved reflective surface, which then focuses and directs the light to f RD at the reference detector. Some of the emitted light from the light generating element travels toward the target medium (e.g., a fluid medium such as a toxic gas). When the emitted light reaches the target medium, it interacts with the target medium. Some of the emitted light is scattered, reflected, and / or re-emitted from the target medium toward the optical element. The optical element directs such scattered or reflected light toward the left reflective surface, which focuses and directs the scattered, reflected, or re-emitted light to f PD at the primary detector. In this sense, the first and second curved reflective surfaces can provide more focused and less dispersed beams of light to the respective primary and reference detectors, which can advantageously increase the reliability and accuracy of the primary and reference detectors.

[0030] The waveguide 405 is located at the top portion of the optical train. As the light emitted from the light generating element travels to / from the target medium, the emitted light can decrease in amplitude without the assistance of the waveguide. The waveguide can help direct the light emitted from the light generating element to / from the target medium with low attenuation. Thus, the waveguide can advantageously avoid the weakening of the light signal reaching the primary and reference detectors.

[0031] In some embodiments, the waveguide is included in or integrally formed with the optical train. The waveguide can be, for example, a slab, (optical) fiber, or channel waveguide. The waveguide may, for example, have a cut-off frequency lower than the frequency of the light emitted by the light generating element.

[0032] Figure 5A cross-sectional view of an example gas detection apparatus having an optical element comprising two partially reflective half parabolic mirrors is shown. The gas detection apparatus 500 includes (e.g., similar to gas detection apparatuses 100, 200, 300, 400) a light generating element (e.g., one or more LEDs), an optical element, a primary detector, and a reference detector. In this example illustration, the optical element 505 includes two (e.g., first and second) partially reflective / transmissive half parabolic mirrors 505A, 505B. The first half parabolic mirror 505B has a focal point f PD at the primary detector. The second half parabolic mirror 505A has a focal point f RD .

[0033] When the light generating element is turned on, light emitted from the light generating element will travel upward toward the optical element. Some of the emitted light from the light generating element is directed by the optical element (e.g., the second half parabolic mirror) to f RD at the reference detector. Some of the emitted light from the light generating element travels through the partially reflective / transmissive half parabolic mirrors toward a target medium (e.g., a fluid medium such as a toxic gas). When the emitted light reaches the target medium, it interacts with the target medium. Some of the emitted light is scattered, reflected, and / or re-emitted from the target medium toward the optical element. The optical element (e.g., the first half parabolic mirror) directs such scattered, reflected, and / or re-emitted light to f PD at the primary detector. In this sense, the first curved reflective surface and the second curved reflective surface can provide more focused and less dispersed beams of light to the respective primary and reference detectors, which can advantageously increase the reliability and accuracy of the primary and reference detectors.

[0034] In some examples, the optical element can include one or more half-silvered mirrors. The one or more half-silvered mirrors can cause a portion of the light emitted by the light generating element to be reflected by the half parabolic mirrors, and can cause another portion of the light emitted by the light generating element to pass through the half parabolic mirrors (e.g., toward the target medium). In various examples, the optical element can be mounted above the light generating element (e.g., via an optical mount).

[0035] While various embodiments have been described with reference to the drawings, other embodiments are possible. For example, the gas detection system can be scaled larger or smaller. The gas detection system can be used in some embodiments in a measurement system that includes a light source and a reference detector / measurement detector. In some embodiments, component placement tolerances of the optically mounted components on the printed circuit board and the mechanical assemblies to which they are attached can require precise alignment or have significant operational tolerances associated with them. The gas detection apparatus disclosed herein can standardize the optical path used by the light generating element (e.g., LED source), the reference detector, and the primary detector, advantageously providing repeatable performance over a wide range of tolerances.

[0036] In some examples, the target media can include a paper tape that produces a metric color stain in response to exposure to a target gas. For example, the target media can be a chemical color-changing material having a unique chemical that reacts with a particular target gas (e.g., carbon monoxide). The target media can change color in response to the presence of the particular gas, such that the target media displays a color stain. In some examples, the target media can change its reflective properties (e.g., the percentage of light reflected by the target media) in response to a reaction with the particular gas. In various examples, the target media can change its spectral contribution (e.g., the frequency of light reflected / absorbed / (re)emitted) in response to a reaction with the particular gas. In some embodiments, the target media can be a gas-reactive media, which may, for example, be a fluid substance.

[0037] In various examples, a lens can be referred to as an“optical feature.” In some embodiments, a mirror can be a surface that fully or partially reflects light. An optical element can be a material having light transmission properties, such as, for example, an acrylic material having integral features to manage light. In various embodiments, an optical element can be formed integrally with an optical train. For example, an optical element may, for example, include two prisms that interact with each other. An optical element may, for example, be partially or fully reflective. In some examples, an optical element can be (a) one or more total internal reflection mirrors. In various examples, an optical element can be molded into or with an optical train.

[0038] Some examples of a gas detection device can include a light generating element. The gas detection device can include an optical train adapted to provide an optical path for light generated by the light generating element to travel to and from a target medium. The optical train can include a first reflective surface and a second reflective surface. The gas detection device can include a primary detector optically coupled with the light generating element. The gas detection device can include a reference detector optically coupled with the light generating element. The gas detection device can include an optical element located within the optical train. The optical element can be adapted to deflect a first light stream generated by the light generating element to the first reflective surface after the first light stream has interacted with the target medium such that the first reflective surface deflects the first light stream to the primary detector. The optical element can be adapted to deflect a second light stream generated by the light generating element to the second reflective surface such that the second reflective surface deflects the second light stream to the reference detector.

[0039] In some examples, the optical train can be an acrylate optical train that is molded in one piece. The optical element can be, for example, a two-sided mirror. In various embodiments, the light generating element, the primary detector, and the reference detector can all be located on a printed circuit board (PCB). Some embodiments can include a processor operably coupled to the light generating element, the primary detector, and the reference detector. A data store can be, for example, operably coupled to the processor and can store instructions that, when executed by the processor, cause the processor to perform operations to identify a target medium. The operations can include, for example, activating the light generating element. The operations can include, for example, receiving a primary signal from the primary detector indicative of a characteristic of the first light stream. The operations can include, for example, receiving a reference signal from the reference detector indicative of the characteristic of the first light stream. The operations can include, for example, determining an identity of the target medium based on the received primary signal.

[0040] Some aspects of the implementations can be implemented as a computer system. For example, various implementations can include digital and / or analog circuitry, computer hardware, firmware, software, or combinations thereof. Elements of apparatuses can be implemented in a computer program product tangibly embodied in an information carrier, e.g., in a machine-readable storage device, for execution by a programmable processor; and methods can be executed by a programmable processor executing a program of instructions to perform functions of various implementations by operating on input data and generating output. Some implementations can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and / or at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, in a computer to perform a certain activity or bring about a certain result. Computer programs can be written in any form of programming language, including compiled or interpreted languages, and they can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0041] Suitable processors for the execution of a program of instructions include, by way of example and not limitation, both general and special purpose microprocessors, and the sole processor or one of multiple processors of any kind of computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. A storage device suitable for tangibly embodying computer program instructions and data includes all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). In some implementations, the processor and / or the components thereof, e.g., can be supplemented by, or incorporated in, a hardware programmable device such as an FPGA (field programmable gate array).

[0042] In some implementations, each system can be programmed with the same or similar information and / or initialized with substantially the same information stored in volatile and / or non-volatile memory. For example, one data interface can be configured to perform automatic configuration, automatic download, and / or automatic update functions when coupled to an appropriate host device, such as a desktop computer or a server.

[0043] In some embodiments, one or more user interface features can be configured to perform specific functions. Exemplary embodiments can be implemented in a computer system that includes a graphical user interface and / or an Internet browser. To provide for interaction with a user, some embodiments can be implemented on a computer having a display device, e.g., an LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer.

[0044] In various embodiments, the system can communicate using suitable communication methods, devices, and techniques. For example, the system can communicate using point-to-point communication with compatible devices (e.g., devices capable of transmitting data to and / or from the system), where messages are transmitted directly from a source to a receiver over a dedicated physical link (e.g., a fiber optic link, an infrared link, an ultrasonic link, point-to-point wiring, a daisy chain). Components of the system can exchange information through analog or digital data communications in any form or medium, including packet-based messages over a communications network. Examples of communications networks include, for example, LANs (local area networks), WANs (wide area networks), MANs (metropolitan area networks), wireless and / or optical networks, and the computers and networks that form the Internet. Other embodiments can transmit messages over a broadcast to all or substantially all devices coupled together through a communications network, for example, by using an omnidirectional radio frequency (RF) signal. Other embodiments can transmit messages that feature high directivity, such as RF signals transmitted using directional (i.e., narrow-beam) antennas or infrared signals that can optionally be used with focusing optics. Other embodiments can be implemented using appropriate interfaces and protocols, such as by way of example and not intended to be limiting: USB 2.0, FireWire, ATA / IDE, RS-232, RS-422, RS-485, 802.11 a / b / g / n, Wi-Fi, WiFi-Direct, Li-Fi, Bluetooth, Ethernet, IrDA, FDDI (Fiber Distributed Data Interface), token ring networks, or frequency, time, or code division multiplexing techniques. Some embodiments can optionally include features such as error checking and correction (ECC) for data integrity, or security measures such as encryption (e.g., WEP) and password protection.

[0045] In various embodiments, a computer system can include a non-transitory memory. The memory can be connected to one or more processors, which can be configured for encoding data and computer-readable instructions, including processor-executable program instructions. The data and computer-readable instructions can be accessible to the one or more processors. The processor-executable program instructions, when executed by the one or more processors, can cause the one or more processors to perform various operations.

[0046] In various embodiments, a computer system can include an Internet of Things (IoT) device. An IoT device can include objects that have embedded electronics, software, sensors, actuators, and network connectivity which enables these objects to collect and exchange data. IoT devices can be used with wired or wireless devices by sending data through an interface to another device. IoT devices can collect useful data and then autonomously make the data flow between other devices.

[0047] A number of implementations have been described. Nevertheless, it will be understood that various modifications can be made. For example, advantageous results can be achieved if steps of the described techniques were performed in a different order, or if components used in the disclosed systems were combined in a different manner, or if the components were supplemented with other components. Therefore, other embodiments are within the scope of the following claims.

Claims

1. A gas detection apparatus (100, 200, 300, 400, 500), comprising: a light generating element (115) configured to generate a first light stream and a second light stream; an optical train (105) configured to provide an optical path for light generated by the light generating element to travel to and from a target medium (110), the optical train comprising a first reflective surface (135) and a second reflective surface (140), wherein the optical train (105) further comprises at least one vertically extending wall (210A, 210B), and wherein the first reflective surface (135) and the second reflective surface (140) are oriented at a 45° angle relative to the at least one vertically extending wall (210A, 210B); a primary detector (125); a reference detector (130); and, an optical element (120) disposed within the optical train (105), wherein the first light stream emitted from the light generating element (115) passes through the optical element (120) to illuminate the target medium (110), and wherein the optical element (120) is configured to: deflect the first light stream to the first reflective surface (135) after the first light stream generated by the light generating element (115) interacts with the target medium (110); deflect the first light stream from the first reflective surface (135) to the primary detector (125); deflect the second light stream generated by the light generating element (115) to the second reflective surface (140); and deflect the second light stream from the second reflective surface (140) to the reference detector (130).

2. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, wherein the optical element (120) is included in the optical train (105) such that the optical element (120) is integrally and unitarily formed with the optical train (105).

3. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, wherein the optical element (120) comprises a double-sided mirror.

4. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, wherein the optical element (120) comprises a beamsplitter.

5. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, further comprising an anti-reflective (AR) coating (310) on at least one surface of the optical train (105) and disposed to avoid stray light from being detected at the primary detector (125) and the reference detector (130).

6. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, further comprising at least one wall (315) disposed between the light generating element (115) and at least one of the primary detector (125) and the reference detector (130) to avoid stray light from being detected at the primary detector (125) and the reference detector (130).

7. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, wherein the optical train (105) further comprises a waveguide (405) that facilitates guiding light emitted from the light generating element (115) to and from the target medium (110).

8. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, wherein: the first reflective surface (135) comprises a first curved reflective surface (415A) configured to concentrate the first light stream at the primary detector (125), and, the second reflective surface (140) comprises a second curved reflective surface (415B) configured to concentrate the second light stream at the reference detector (130).

9. The gas detection apparatus (100, 200, 300, 400, 500) of claim 1, further comprising: a processor (150) operably coupled to the light generating element (115), the primary detector (125), and the reference detector (130); and, a data store (160) operably coupled to the processor (150) and storing instructions that, when executed by the processor (150), cause the processor (150) to perform operations to identify the target medium (110), the operations comprising: activating the light generating element (115); receiving a primary signal from the primary detector (125) indicative of a characteristic of the first light stream; receiving a reference signal from the reference detector (130) indicative of a characteristic of the second light stream; determining an identity of the target medium (110) based on the received primary signal.

10. A gas detection apparatus (100, 200, 300, 400, 500) comprising: a light generating element (115) configured to generate light comprising a first light stream and a second light stream; a lens (305) to focus light generated by the light generating element (115); an optical train (105) configured to provide an optical path for light generated by the light generating element (115) to travel to and from a target medium (110), the optical train (105) comprising a first reflective surface (135) and a second reflective surface (140), wherein the optical train (105) further comprises at least one vertically extending wall (210A, 210B), and wherein the first reflective surface (135) and the second reflective surface (140) are oriented at a 45° angle with respect to the at least one vertically extending wall (210A, 210B); a primary detector (125); a reference detector (130); and, an optical element (120) disposed within the optical train (105), wherein the first light stream emitted from the light-generating element (115) passes through the optical element (120) to illuminate the target medium (110), and wherein the optical element (120) is configured to: after the first light stream generated by the light-generating element (115) interacts with the target medium (110), deflect the first light stream to the first reflective surface (135); deflect the first light stream from the first reflective surface (135) to the primary detector (125); deflect the second light stream generated by the light-generating element (115) to the second reflective surface (140); and deflect the second light stream from the second reflective surface (140) to the reference detector (130).

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