阅读说明：本技术 风道安装式空气质量监测系统、方法和装置 (Air duct installation type air quality monitoring system, method and device ) 是由 V·I·拉夫洛夫斯基 凯文·R·哈特 艾伦·J·麦克唐纳德 于 2018-01-18 设计创作，主要内容包括：本发明提供一种在风道系统中使用的空气质量监测装置。该装置包括具有至少一个空气交换端口的外壳、至少一个光学系统和多个传感器。该空气交换端口产生穿过外壳的气流通道,而光学系统提供穿过该气流通道的光。多个具有通向气流通道的通路的传感器配置为测量气流的空气质量数据。至少一个微控制器配置为处理测量的空气质量数据。至少一个通信系统配置为将处理后的空气质量数据传送至外部网络。(The invention provides an air quality monitoring device used in an air duct system. The apparatus includes a housing having at least one air exchange port, at least one optical system, and a plurality of sensors. The air exchange port creates an airflow channel through the housing and the optical system provides light through the airflow channel. A plurality of sensors having a passageway to the airflow channel are configured to measure air quality data of the airflow. The at least one microcontroller is configured to process the measured air quality data. At least one communication system is configured to transmit the processed air quality data to an external network.)

1. An air quality monitoring device comprising:

a housing, the housing comprising:

at least one air exchange port having an inlet aperture and an outlet aperture, the at least one air exchange port creating at least one airflow channel through the housing;

at least one optical system providing light through the airflow channel;

at least one microcontroller configured to process the measured air quality data; and

a plurality of sensors having access to the airflow channel, the plurality of sensors configured to measure air quality data;

at least one communication system configured to transmit the processed air quality data to an external network; and

a power supply device that supplies power to the device.

2. The apparatus of claim 1, wherein the first and second electrodes are disposed on opposite sides of the housing,

wherein the housing has at least two air exchange ports creating at least two airflow channels, each of the at least two air exchange ports having an inlet aperture and an outlet aperture,

wherein the at least one optical system provides light through at least one of the at least two airflow channels; and

wherein the plurality of sensors have access to each of the at least two airflow channels and are configured to measure air quality data for each of the at least two airflows.

3. The apparatus of claim 2, wherein each of the at least two air exchange ports is symmetrical, has a high interior surface finish quality and has a geometry necessary to ensure smooth laminar airflow through the plurality of sensors at all operating speeds in the duct system.

4. The apparatus of claim 1, wherein the air exchange port has a high interior surface finish quality and has a geometry necessary to ensure smooth laminar air flow over the plurality of sensors at all operating speeds in the duct system.

5. The apparatus of claim 1, wherein the first and second electrodes are disposed on opposite sides of the housing,

wherein the at least one air exchange port creates at least two airflow channels,

wherein the at least one optical system provides light through at least one of the at least two airflow channels; and

wherein the plurality of sensors have access to each of the at least two airflow channels and are configured to measure air quality data for each of the at least two airflows.

6. The apparatus of claim 1, wherein the at least one communication system is configured to connect to a cloud computing system.

7. The apparatus of claim 1, wherein the at least one communication system is configured to receive and transmit data over a wired or wireless connection.

8. The apparatus of claim 1, wherein the at least one communication system is configured to send control signals to HVAC equipment over a wired or wireless connection.

9. The apparatus of claim 1, wherein the at least one communication system comprises an external antenna.

10. The apparatus of claim 1, wherein the at least one communication system comprises an onboard wireless transceiver with an integrated antenna.

11. The apparatus of claim 1, wherein the first and second electrodes are disposed on opposite sides of the housing,

wherein the at least one communication system is configured to receive incoming out-of-band data, and

wherein the at least one microcontroller is configured to process the received input out-of-band data in conjunction with the measured air quality data.

12. The apparatus of claim 1, wherein the at least one optical system comprises a laser assembly.

13. The device of claim 1, wherein the power supply device is powered by a wired connection.

14. The apparatus of claim 1, wherein the plurality of sensors comprises at least one flow sensor located within the housing.

15. The apparatus of claim 1, wherein the plurality of sensors comprises at least one flow sensor located within the airflow channel.

16. The apparatus of claim 1, wherein the plurality of sensors comprises sensors selected from the group consisting of thermal sensors, acoustic sensors, optical sensors, and any combination thereof.

17. The apparatus of claim 1, wherein the flow sensor comprises a bi-directional flow sensor.

18. The apparatus of claim 1, further comprising a mounting fixture that enables the housing to be mounted to a wall of a ductwork or air handling conduit, wherein the air exchange channel is located between the wall and a center of the ductwork or air handling conduit.

19. The apparatus of claim 18, further comprising sensors for determining the presence, orientation and location of the mounting fixture relative to the position of the apparatus.

20. The apparatus of claim 1, further comprising a mounting fixture configured to rotate along an axis of rotation perpendicular to the airflow channel.

21. The apparatus of claim 1, wherein the at least one airflow channel comprises a narrowed middle portion.

22. A method of monitoring the condition of an air filter using the apparatus of claim 1.

Technical Field

The present disclosure relates generally to Heating Ventilation and Air Conditioning (HVAC) systems, and more particularly to a system and method for quantifying and recording indoor air quality data in a ducted system.

Background

Residential owners and facility managers typically rely on professional contractors or building engineers to spot check heating ventilation and air conditioning ("HVAC") systems to determine if the volume of air exhausted by an entire house or other building is sufficient; quantifying the level of the contaminant; or to determine the source of poor air quality. Since these spot checks are done through a series of labor intensive manual processes, they are not frequent, costly and unreliable. This work involves sampling air using a variety of hand-held devices, including temperature/humidity meters, gas flow meters, particle meters, and specialized devices called capture hoods that allow quantification of the amount of air flow outside of a particular duct. Spot checks typically fail to identify transient faults driven by system timing, diurnal atmospheric modes, or very rare events. The sampling must be done at multiple locations, which greatly increases the time required to complete the test. In large buildings, such audits may only be performed once a year, so that intervention in poor air quality can only be performed in extreme cases where the resident is clearly aware.

Disclosure of Invention

It is an object of the present invention to provide an air quality sensor monitoring system and device that measures multiple air quality indicators in an integrated device driven by forced airflow in any ducted system. The system has an Air Quality Monitoring (AQM) device that can be used to quantify one or more air quality parameters, such as temperature, humidity, pressure, mass flow, air flow rate, Volatile Organic Carbon (VOC), nitrogen oxides (NOx), certain volatile gases (e.g., formaldehyde), oxygen (O)₂) Carbon dioxide (CO)₂) Particulate matter (PM2.5, PM10), and particulate composition (type/diameter). The AQM comprises a high resolution Optical Particle Counter (OPC) with high spatial coherence and high signal bandwidth. AQM, which measures Indoor Air Quality (IAQ), is a passive device because it does not require moving parts such as pumps or fans, and the air is exhausted through a number of low impedance ports in the monitor. The monitor is mounted in the wind tunnel perpendicular to the axis of air flow and is designed to reduce turbulence induced in the air flow.

The apparatus includes a plurality of sensors, one or more microcontrollers, a power supply, an optical system, and a housing. In some embodiments, the data and power are provided over a wired connection. In other embodiments, the data connection is accomplished through an onboard wireless transceiver having an integrated antenna or an external antenna connected through a coaxial cable. The device measures the displacement or mass flow of air flowing through by optical, thermal or acoustic means, allowing the concentration of any contaminants to be calculated. The volume compensated measurement allows the system to estimate the overall pollution load rather than just making a relative measurement. The user may enter out-of-band data (e.g., the size of the duct) so that the device can feedback the total amount of each contaminant. Since the mixing conditions are good in most ductwork, accurate evaluation is possible even if a very small cross-section is sampled. The use of continuous sampling allows for longer sampling times by reducing the number of samples, making the device statistically robust. Due to the symmetry of the air exchange ports and the bi-directionality of the flow sensing elements, the AQM does not need to know the flow direction. The ports are symmetrical, have a high internal surface finish quality, and have the necessary geometry to ensure smooth laminar flow of air past the sensor at all operating speeds/displacements in the ductwork. Therefore, the data quality does not change regardless of the mounting direction. The AQM can thus be mounted upside down, or on either side of the duct, without loss of performance. The airflow channels of the AQM can be straight or curved. In one embodiment, the passageway has a nozzle or narrowed middle portion (e.g., hourglass shape) to accelerate the gas flow as it enters the port and traverses the device along the passageway. In this way, aerosols suspended in the air flow can also be concentrated as the air flow passes through the device along the passageway. Higher air flow velocities prevent settling of the suspended aerosol as it passes through the critical sensing area. The increase in the concentration of aerosol suspended in the gas stream improves the detection efficiency of the optical particle counter. The nozzle ensures that the aerosol passes through the area of maximum optical power density and produces the strongest response in the OPC detector.

In one embodiment, the device may have a mounting fixture with which the probe can be quickly installed (inserted and removed) from the wind tunnel. The mounting fixture holds the device in place relative to a duct or other air handling conduit. The air duct may be formed of metal, plastic, duct board or other suitable material, or may be formed of other structural members, such as wall tiles or ceiling tiles. The air duct may have a square, rectangular, circular or oval cross-section and may be rigid or flexible. The mounting fixture ensures that the device can be securely mounted on a duct or air handling conduit of all the above types, shapes and materials. The mounting clip has a plurality of interfaces that ensure that the gasket forms a continuous mating surface on both flat and curved surfaces. This minimizes leakage and ensures that installation of the device does not affect the efficiency of the HVAC system.

Drawings

The disclosure may be more completely understood in consideration of the following description of various exemplary embodiments in connection with the accompanying drawings, in which:

figure 1 illustrates a perspective view of a fully assembled AQM device in some embodiments.

Fig. 2 is a side view of the device of fig. 1 in some embodiments.

FIG. 3 is an exploded side view of the device of FIG. 1 in some embodiments;

FIG. 4 is a cross-sectional top view of the device of FIG. 1 in some embodiments;

FIG. 5 is an exploded top perspective view of the device of FIG. 1 in some embodiments;

FIG. 6 is an exploded bottom perspective view of the device of FIG. 1 in some embodiments;

fig. 7 is a front perspective view of a mounting clip optionally used in conjunction with the device of fig. 1 in some embodiments.

FIG. 8 is a rear perspective view of the mounting clip of FIG. 7 in some embodiments.

FIG. 9 is a perspective view of the device of FIG. 1 and the mounting clip of FIG. 7 in a pre-mated configuration, in some embodiments;

fig. 10 is a perspective view of the device of fig. 1 and the mounting clip of fig. 7 in a mated configuration, in some embodiments.

The present disclosure is susceptible to various modifications and alternative forms, some of which have been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular exemplary embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

Detailed Description

The following description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The following description and the annexed drawings, which are not necessarily to scale, illustrate certain exemplary embodiments and are not intended to limit the scope of the disclosure. The illustrated embodiments are exemplary in nature. Selected features of any example embodiment may be incorporated into additional embodiments unless explicitly stated to the contrary.

The present invention is an Air Quality Monitoring (AQM) device that measures multiple air quality indicators in an integrated device driven by forced air flow in any air handling duct system, such as a ductwork system.

The device may be installed in any duct to measure the indoor air quality of a room or area upstream of the installation location. A plurality of such AQM devices may be deployed at different nodes in the HVAC system and in the supply and/or return airflow branches. In this manner, the AQM is able to identify the origin of a pollution event and quantify the performance of the air purification device, including devices integrated with the HVAC system and independent room filters. Cross-referencing between two or more AQMs can indicate that the pollution caused by an environment not in the area originates from a room or area upstream of the installation site. In other cases, the apparatus may be installed in the return air system near a fire or other air handling equipment, before an air filter or other air purification system. By being located in the return air system, particularly in plenum boxes or other areas where multiple air streams converge into a larger duct or air handling duct, the air of the entire house or building can be measured. The homogenization of an entire home or building allows the IAQ of an entire structure or portion thereof to be effectively measured using a single sensor. In some buildings and dwellings, especially in smaller buildings and dwellings, a single device may be used to assess the composition of the circulating air, while in larger buildings one or more devices may be used for each floor or zone in a floor. In one embodiment, out-of-band data may be utilized to determine the origin of a contamination event without deploying multiple devices. This data may be data reported by building occupants, or may be obtained by tracking the occupant's location in a home or other structure. In some cases, a contamination event may be caused by the presence or activity of a resident in a home or building. By correlating the location of the household with historical pollution data from any available AQM devices, the AQM or host control and management software layer (e.g., a software layer implemented in the cloud) can infer the likely origins of events measured and logged by the AQM devices. In other deployments, multiple devices may be arranged upstream and downstream of the filter or air purifier to differentially measure the levels of all sensor values. In this way, the performance of the filter and the air cleaning apparatus can be quantified with high resolution.

In one embodiment, differential pressure measurements from on-board pressure sensors on both devices can be used to measure the loading and aging of the filter to detect when the filter needs to be replaced. This eliminates the need for user intervention and ensures that the amount of HVAC system displacement is sufficient to ensure a good IAQ throughout the house or building.

In one embodiment, the loading of the filter may be detected by computationally deriving a volume regulated total particulate loading tracking system. For a known cross-sectional area of the wind tunnel, the flow-corrected particle count may be used to calculate the expected particle load for the entire wind tunnel. This value is then subtracted from the filter loading model established for the given filter media and surface area. When the available load capacity is exhausted, the filter is considered to be exhausted. In another embodiment, sensor fusion is used to ensure more reliable particulate load filter life calculations by tracking the decay in flow rate and pressure as the filter ages. In particular, the pressure differential between fan states is of instructive significance for measuring filter load. The current pressure differential during the fan enable or disable event may be compared to historical data to identify an end-of-life condition of the filter. This has a complementary effect, as the system may have incorrect data on filter media, filter surface area, filter efficiency, or there may be multiple filters or system leaks that change the rate at which contaminants increase.

In one embodiment, the device may be implemented as a long probe, which ensures that a boundary layer of turbulent or stagnant air at the airway wall is avoided. The device may have multiple apertures to accommodate additional sensors without increasing the overall size of the device. A sensor of precise flow rate is required to be paired with a flow sensor in the same orifice for real-time flow correction.

In one embodiment, the device may have a mounting clip that enables the device to be attached to a wind tunnel or air handling conduit. The mounting fixture also facilitates rapid insertion and removal of the probe from the wind tunnel. The duct may be constructed of metal, plastic, duct board or other material, or may be formed of other structural members, such as wall tiles or ceiling tiles. The air duct may be rectangular or circular and may be rigid or flexible. The mounting clip ensures compatibility with air ducts or air handling ducts of all the above types, shapes and materials. The mounting clip may have multiple interfaces that ensure that the gasket forms a continuous mating surface on both flat and curved surfaces. This minimizes leakage and ensures that installation of the device does not affect the efficiency of the HVAC system.

In one embodiment, the mounting fixture has a channel that matches the outer profile of the probe housing so that the probe can slide along and be fully supported by the channel. The mounting fixture is secured to the air chute by fasteners such that the channel for the probe remains horizontal and parallel to the axis of airflow in the air chute. In this way, when the probe is inserted into the mounting fixture, the airflow is aligned with the aperture. The mounting clip may have a plurality of inner surfaces of different diameters to ensure compatibility with flat and circular duct surfaces. Where the air duct surfaces are circular, there are one or more surfaces, each having a radius of curvature that matches a particular type or pattern of curved air duct. The mounting fixture may use gasket material to seal the interface between the surfaces and the air chute. The mounting fixture may include features such as magnets, mechanical bayonets, optical markers, diaphragms, optical reflectors, or metal components that allow the probe to detect that it has been mounted in the channel of the mounting fixture. In this way, the probe can disable any components that need to remain inactive outside of the wind tunnel. The device may comprise a mechanical, optical or magnetic sensor for detecting the presence and orientation of features in the mounting fixture.

In one embodiment, the laser that is part of the optical particle counter may be disabled to ensure that the user is not accidentally illuminated by stray light from the laser before inserting the powered device. When the probe is installed, the device detects the presence of one of these features and allows OPC to use a laser. The device housing may have one or more mechanical bayonets or apertures that interface with features in the mounting fixture, which allow the user to insert the device to the correct depth during installation.

As the sample air passes through the device, it passes through one or more sensors. The device may sense at least one parameter and store the sensed parameter in volatile or non-volatile memory. The device can then flow compensate the value or simply record the flow at the time of measurement for future flow correction or compensation. The device continuously samples, but if the measurements do not change, the data can be discarded; this is an example of an optimization that the device can be used to maximize on-board memory efficiency. Other embodiments may use byte-saving encoding methods such as huffman coding, compression algorithms, or dynamic data rates to increase the amount of data that can be buffered on-board. The device may choose to change its sensor bandwidth according to the rate of change or deviation from a reference. In this way, useful data can be captured with higher bandwidth. The device may also continuously down-sample previously recorded data to ensure that new data continues to be recorded when memory is about to be depleted.

The device may operate in a stand-alone manner or may be connected to a remote computing system to continuously clear its cache. The device may have one or more onboard communication systems, including wired and wireless standards for sending telemetry commands and for receiving commands and configuration data. The wired standard may be any of the transmission lines used in industrial environments and may be a differential wire level standard such as RS-422 or RS-485. The communication protocol implemented in the wired monitor is defined in the device software and may be Modbus, BACnet, LonTalk or any other protocol scheme, including proprietary protocol schemes. Wireless embodiments may utilize transceivers and antennas that extend outside of the wind tunnel, and may be implemented in Bluetooth, Bluetooth Intelligence, Wi-Fi, Z-Wave, ZigBee, or any other wireless protocol.

In one embodiment, the device may generate the control signal based on one or more air quality parameters. The signal may be sent over a wired network connected to the device, via a direct wireless connection to the target device, via a hub that allows interfacing with devices having mismatched transceivers, or via a cloud connection that is mediated through the API layers of both devices. The device may adjust the control signal to maintain the sensed parameter within a particular threshold. Such adjustments may be achieved by a PID loop or other feedback loop that allows the device to achieve a target value for any given parameter. The target device may be any type of controllable end effector including a bypass valve, an automatic vent, a fan drive, an air circulation device, an automatic window, a stove, an air purifier, a heater, or other system within a house or building. The control signal may be used by the target device to adjust its own performance, or the target device may be directly actuated by the control signal. One example is an air purifier having a variable speed drive mechanism. Thus, the control signal is a demand control loop that ensures that the air purifier is always operating at a sufficient rate to maintain the target parameter within a desired range. Any control system may be bound to control signals through an API in a similar manner. In one embodiment, these APIs may be implemented as cloud-to-cloud APIs. The actuated device uses internal parameters or API-defined settings to control the dynamic range and slew rate of the actuation, thereby ensuring that the control signal does not overdrive the target device.

In one embodiment, the device may measure the rate of change that the HVAC system is capable of implementing in firmware or cloud by measuring the rate of change relative to the control signal. These measurements can be used to derive a hysteresis of the HVAC system for each parameter, and in this way the device can adjust its use of control signals without any a priori knowledge about the HVAC system structure, the size of the building, the effectiveness of the target device being actuated, or any other parameter not measured by the device. When the device is operated in a ducted environment, contamination can slowly build up from particles and other contaminants present in the air stream. The device may use smooth and straight air channels to minimize turbulence in the air flow and avoid low pressure areas that induce the deposition of suspended particles or other contaminants. In addition, the plastic material of the housing and the orifice can be produced by materials and processes that produce lower surface energies, which can greatly reduce the adhesion of particles and other contaminants on these surfaces.

In one embodiment, the device housing may be constructed of a conductive material or contain a conductive additive. In another embodiment, the housing material is non-conductive, but is treated with a conductive coating, coating or sprayed layer to make it conductive. In some embodiments, the housing is in physical contact with exposed conductive contacts on the surface of the printed circuit board. These contacts are connected to the earth of the electrical system and ensure that any charge accumulated in the housing can be dissipated. In this way, particles that may be positively or negatively charged are not electrostatically attracted to the device housing or component, which reduces the affinity of the exposed surface for interaction with particles or other contaminants. Thus, any contamination is easily removed when the device is removed from the mounting fixture. The user need only blow air into the orifice or may alternatively use a moving air source, such as canned air, a compressor, a dust blower, or even use a vacuum.

In one embodiment, the apparatus may be used as an Air Quality Monitor (AQM) and may be configured to sense one or more parameters related to the Indoor Air Quality (IAQ) of a home or building. The device may utilize sensor fusion to minimize the effects of sensor drift and other error sources. For example, the device may be configured to monitor one or more parameters in the airflow using its sensor array. In one embodiment, the optical particle counter sensor may measure air velocity by performing a statistical analysis of the travel time of particles passing through the detector. The device will simultaneously take measurements using an acoustic or thermal flow sensor, which may be implemented as a component suspended on a wire harness in the flow regime or as a component on the surface of a PCB with access to the flow regime. By tracking the consistency between these two measurements over a large number of samples, the performance of the optical transit time measurement can be used to measure drift in a thermal or acoustic sensor. In this way, the stability of optical flow measurement can be combined with the accuracy and repeatability of thermal or acoustic flow sensors. In some embodiments, the one or more parameters may be provided by an external device or system. Thus, the device does not require any special sensors, it can capture data from other devices in the HVAC system through wired or wireless communication channels. In some embodiments, the device has wired and wireless interfaces to maximize interoperability with other devices in the HVAC system. In this way, the device may negotiate with all devices in its local environment, either individually or through a hub.

Figure 1 illustrates a perspective view of a fully assembled AQM device in some embodiments.

Fig. 2 is a side view of the device of fig. 1 in some embodiments. Referring now to the drawings, fig. 1 and 2 are assembled views of the device 100 in some embodiments assembled with an upper shell 102 and a lower shell 104. The upper shell 102 and the lower shell 104 may be coupled by fasteners (not shown) inserted in the screw holes 174. The threaded bore 174 may have a depth such that the top of the fastener (not shown) is below the surface of the upper shell 102. This can reduce contact of the user or installer with the fastener (not shown) and prevent electrostatic discharge events from being conducted into the printed circuit board (not shown).

In some embodiments, the device 100 may include an interconnect portion for receiving a lead-to-device interconnect that may receive a terminal board (fig. 3, 144) or other wire-to-board interconnect having two or more locations. The housing may have one or more air intake apertures or nozzles 106, 108 that allow air to be drawn into the device 100 from the air flow. The shape of the apertures 106, 108 allows for a low impedance and adjustable internal air velocity through the aspect ratio of the inner surfaces of the apertures 106, 108. In some embodiments, the device 100 may have an antenna 142 to increase the range of the wireless connection. In other embodiments of the device 100, internal antennas mounted on the radio frequency transceiver (fig. 5, 138) or other locations on the printed circuit board (fig. 5, 103) may be used. In some embodiments, the device 100 may be mounted such that the bottom surfaces 112 of the intake apertures 106 and 108 face downward in the direction of gravity. Thus, deposits can accumulate on the bottom surface 112 where they do not affect the sensor and can be easily removed by inserting a cleaning device into the apertures 106 and 108.

Fig. 2 is a side view of the device 100 of fig. 1 assembled with the upper shell 102 and the lower shell 104 in some embodiments. This figure shows schematically and intuitively how air intersects the device and passes through the orifices 106 and 108. In some embodiments, the apertures 106, 108 may have a straight or curved cross-section across the enclosure formed by 102 and 104. In other embodiments, the apertures 106 and 108 may have a nozzle cross-section or other three-dimensional shape to enable exhaust volume management through the sensor passage hole 110, or to adjust the detection volume formed by the intersection of a beam line (not shown) with the gas flow in the sampling apertures 106 and 08. The ports 106 and 108 are located away from the mounting plate bayonet (fig. 1, 124) so that they are, when mounted through the mounting plate (not shown), away from the wall of the duct or other conduit in which the device 100 is located. This ensures that the apertures 106 and 108 are not in the boundary regions near the walls of the air duct or conduit where air may be stagnant, moving more slowly or turbulent. The antenna 142 may be of different styles and sizes or may not be present at all, depending on the radio frequency environment. In some embodiments, the antenna 142 is larger to have higher gain and achieve greater range. The lower housing 104 may accommodate the mounting requirements of a plurality of different antennas 142.

Fig. 3 is an exploded side view of the device 100 of fig. 1 in some embodiments, the device 100 having an upper housing 102, a lower housing 104, apertures 106, 108, and a printed circuit board 103 populated with electronic components. The terminal plate 144 provides a connection to an external power source. In some embodiments, the terminal block 144 may have additional locations to accommodate multiple data lines for wired telemetry transmission. Also shown are laser mount 122, laser 160, and optical module 114 that provides a light source for optical particle counting functions. The laser mount 122 secures the laser 160 to the printed circuit board 103 and ensures that the beam line 166 is aligned with the optical module 114. There may be a plurality of different optical modules 114 to accommodate different lasers 160 that emit beam lines 166 having different spot sizes or beam divergence angles. The antenna 142 is connected to the PCB103 or a component on the PCB via the cable 140.

Fig. 4 is a cross-sectional top view of the device 100 of fig. 1 in some embodiments. Fig. 4 shows how the laser 160 is mounted such that its beam line 166 passes through the sensor passage aperture 110 into the laser-terminated beam dump 120. The sensor via 110 ensures that as little stray light as possible enters the photodiode or other sensor, since the photodiode or other sensor is completely protected by the upper shell 102 except for the via 110. In one embodiment, the PCB mounted optical, acoustic or thermal flow sensor 156 is in the same orifice 106 as the optical sensor assembled from the laser 160, the via 110 and the beam dump 120, in such a way that the precise flow or displacement as seen by the optical sensor can be measured. This allows the device to compensate for variations in the flow in the wind tunnel and through the orifices 106 and 108. The beam line 166 passes through the sensor aperture 110, through the detector, and terminates in the beam dump 120 so that light does not escape the device housing formed by the upper and lower shells 102, 104. The sensor 136 may be a mechanical, optical or magnetic sensor arranged to detect the presence and orientation of the mounting plate 273. One or more sensors 136 may be arranged to detect the position of the device 100 relative to the insertion depth in the mounting plate 273.

Fig. 5 is an exploded top perspective view of the device 100 of fig. 1 in some embodiments. In this embodiment, the radio frequency transceiver 138 is mounted on the PCB103 and then connected to the antenna 142 via the antenna coaxial cable 140. The antenna 142 is mounted in the joint formed by the upper and lower shells 102, 104 in the antenna mounting structure 128. The power supply 170 for the device is mounted on the PCB103 and is powered by an external power supply (fig. 6, 144) connected through a terminal board. One or more microcontrollers 168 are mounted on the PCB103 to control the optical particle counting function and are additionally responsible for all other control aspects of the circuit board. In this embodiment, the microcontroller 168 also provides off-board data access capability through interaction with the transceiver 138. To provide a very low noise environment for the analog front end of the device at the OPC detectors on the back side of the PCB103 opposite the photodiodes 154, shielding functionality is provided on the PCB103 by mounting a radio frequency shield 132. The laser 160 is connected to the PCB103 power supply via laser interconnect pads 162. Heat sink slots 134 are provided in PCB103 to reduce self-heating of device 100 and to reduce heat transfer from one half of the board to the other. The lower shell 104 has an additional sensor access hole 110 through which a different sensor mounted on the printed circuit board 103 can contact air flowing through the second sampling orifice (see fig. 1, 108). One or more alignment pins 172 are provided throughout the lower housing 104 assembly for positioning the PCB103 to complete alignment of the PCB-mounted sensors 154, 156, 158 with the lower housing 104.

Fig. 6 is an exploded bottom perspective view of the device 100 of fig. 1 in some embodiments. The device may have an optical, thermal or acoustic flow sensor 156 for determining whether air is flowing through the aerosol sampling orifice 106. The sensor is able to accurately determine the flow through the particular orifice for the sensor where air flow rate or mass displacement is critical. The housing contains a laser 160 mechanically secured by a laser mount 122; the clip and laser assembly may be secured to any of a plurality of holes in the PCB103 that form the optical track 164 to accommodate the focal length of the series of lasers 160. This allows the laser 160 to be replaced without changing the PCB103 or the housing 102, 104. The heat sink 134 isolates the surrounding sensor 158 from the heat generated by the power supply 170, transceiver 138, and laser 160.

The PCB-mounted flow sensor 156 is arranged side-by-side with sensors located in the same channel 106 and therefore experiences the same speed and mass displacement as the other sensors. The laser beam line 166 is constrained by the optical baffle 118 as part of the optical module 114. The optical module 114 is mounted to the PCB103 via a hole in the PCB, which constitutes an optical module mating surface 116. A diagnostic LED 152 is used to selectively confirm the sensitivity of the photodiode 154 and may be used to provide a baseline measurement to the photodiode 154 that may be used for calibration of the apparatus 100. To prevent air from escaping into the housing 104, an air leakage prevention cover 130 is disposed at the side of the air flow channel 108 to prevent air from flowing through the heat dissipation groove 134. Mounted on the front of the PCB103 are user operated buttons 146 and RGB LEDs 148 which are visible on the outside of the housing 104 through a light pipe 150. Both the button 146 and the LED 148 are managed by the microcontroller 168. One or more interlock sensors 136 are mounted on the PCB103, which in one embodiment are hall effect sensors, and are responsive to an external magnet, which in one embodiment is located in a magnet cavity (not shown) of a mounting plate (not shown). The lower case 104 has two terminal passage holes 126 which are fitted with terminal plates 144 mounted on the PCB103 to supply external power to the device 100.

Fig. 7 is a front perspective view of a mounting clip optionally used in conjunction with the device of fig. 1 in some embodiments. In one embodiment, the mounting fixture may be a mounting plate 273, the mounting plate 273 having two or more screw access holes 276 for securing the mounting plate to the air chute using fasteners 290 (not shown). The mounting plate has a device channel that supports the probe when the probe is inserted. During insertion, the probe is held in place by bayonet locking clips 274, the bayonet locking clips 274 aligning with the bayonets (not shown) in the upper (not shown) and lower (not shown) housings of the device (not shown). The inner surface of the mounting plate 273 has a zero taper track and one or more retaining clips 274 that ensure that the device is well supported when mounted in the mounting plate 273. In this way, the device can remain stationary even under the influence of vibrations or fast moving air streams.

FIG. 8 is a rear perspective view of the mounting clip of FIG. 7 in some embodiments. The mounting plate 273 has two faces 282, 284 which bear against the outer wall of the air chute or air handling conduit. If the duct is mounted flat, the smaller port 282 will be in contact with the duct, and if the duct is circular, the larger port 284 will be in contact with the duct. In the case of a larger duct, the curved engagement edge 286 would contact the mounting duct. The mounting plate 273 also contains a cavity 278 that is used to receive a magnet or other detection target inserted therein that will interact with an interlock sensor (not shown) when the device is mounted in the mounting plate 273. The cavity 278 has a retaining clip 280 integral therewith, the retaining clip 280 for retaining the assay target within the cavity 278.

Fig. 9 and 10 are perspective views of the device of fig. 1 and the mounting clip of fig. 7 in pre-and post-mating configurations, respectively, with the mounting plate bayonet 124 configured to mate with the bayonet locking clip 274 and lock the device 100, according to some embodiments. The seam at the junction of the two housing pieces 102, 104 has an aperture at the front side of the lower shell 104 provided with a light pipe 150 to visualize light from RGB LEDs (not shown) mounted on a PCB (not shown) at the front side of the device. A second hole in the seam between the housings provides access for a button 146, which button 146 may be used to interact with a microcontroller mounted on the PCB. The mounting plate 273 is secured to the air chute or air handling conduit by fasteners 290. The fastener 290 may be a magnet, screw, toggle bolt, or other device.

Referring to FIG. 10, the mounting plate 273 may be attached to the air chute by fasteners 290. The mounting plate 273 is inserted into a hole in the air chute having a diameter that allows it to accommodate either the inner air chute interface 282 or the outer air chute interface 284. The device 100 can be quickly and easily removed from the mounting plate 273 by pulling the device 100 off the bayonet locking clips 274 with sufficient force. The device 100 may be removed from the mounting plate 273 for servicing. When the service is complete, the device 100 can be reinserted by sliding the device 100 into the channel of the mounting plate 273. The device 100 may be inserted to any depth or returned to its full depth by engaging the retaining clip 274 with the bayonet 124 of the mounting plate.

Although the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It should be understood that the invention is not limited to the exemplary embodiments set forth herein.