Flow rate detection for aspirated smoke detection systems

Abstract

Methods, devices, and systems for flow rate detection of an aspirated smoke detection system are described herein. In one embodiment, an apparatus includes a flow rate sensor for an aspirated smoke detection system including a flow chamber allowing gas to flow through the flow chamber and a receive coil located inside the flow chamber, wherein the processor is to execute instructions to receive a signal from the receive coil and determine a flow rate of the gas through the flow chamber based on the signal.

Description

Technical Field

[0001] The present disclosure relates to a method, apparatus and system for flow rate detection in an aspirating smoke detection system. Background Art

[0002] Facilities (e.g., buildings), such as commercial facilities, office buildings, hospitals, etc., may have an alarm system that can be triggered during an emergency (e.g., a fire) to warn occupants to evacuate. For example, the alarm system may include a control panel (e.g., a fire control panel) and a plurality of aspirating smoke detector devices located throughout the facility (e.g., on different floors and / or in different rooms of the facility), included in an aspirating smoke detection system that can detect dangerous events, such as smoke generation (e.g., due to a fire or other cause). The aspirating smoke detectors can transmit signals to the control panel to notify the building manager, occupants of the facility, emergency services, etc. of the dangerous event via an alarm or other mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Figure 1 An aspirating smoke detection system with a flow rate sensor according to one or more embodiments of the present disclosure is disclosed.

[0004] Figure 2 is a top view of one example of a flow rate sensor having a receiving coil and a transmitting coil according to one or more embodiments of the present disclosure.

[0005] Figure 3A is a top view of one example of a flow rate sensor having a magnet and a receiving coil in a first position according to one or more embodiments of the present disclosure.

[0006] Figure 3B is a top view of one example of a flow rate sensor with a magnet and a receiving coil in a second position according to one or more embodiments of the present disclosure.

[0007] Figure 4 The invention relates to a controller for flow rate detection of an aspirating smoke detection system according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0008] Methods, devices, and systems for flow rate detection for an aspirating smoke detection system are described herein. A device includes a flow rate sensor for an aspirating smoke detection system, the aspirating smoke detection system including a flow chamber and a receiving coil, the flow chamber allowing gas to flow through the flow chamber, the receiving coil being located inside the flow chamber, wherein a processor is used to execute instructions to receive a signal from the receiving coil and determine a flow rate of the gas through the flow chamber based on the signal.

[0009] An aspirating smoke detector device may be utilized as part of an aspirating smoke detection system in a facility to detect hazardous events by detecting the presence of smoke. The aspirating smoke detector device may draw gas (e.g., air, via a blower) from the facility to a sensor through a network of ducts throughout the facility. The duct network may include a duct sampling network. The sensor may sample gas in the duct sampling network to determine whether the gas sampled from the facility includes smoke particles. In response to detecting smoke particles, the aspirating smoke detector device may send a signal to a control panel in the facility to signal that smoke particles have been detected in an area of ​​the facility where the aspirating smoke detector is monitoring and sampling gas therein.

[0010] As described above, in order for an aspirating smoke detector device to sample gas to detect smoke particles, the gas must be transported from the sampling location to the aspirating smoke detector device. Therefore, the aspirating smoke detector device may utilize a network of pipes throughout the facility to transport the sampled gas to the aspirating smoke detector device. For example, the pipe sampling network may transport gas from an area of ​​the facility to the aspirating smoke detector device for testing.

[0011] To ensure that the aspirating smoke detector device is properly sampling the gas, the gas should flow through the sampling pipe network to the aspirating smoke detector device at a known flow rate. Determining the flow rate of the gas ensures that the aspirating smoke detector device is operating properly. Additionally, sensing and monitoring the flow rate of the gas through the sampling pipe network may be a regulatory requirement in some jurisdictions to ensure safe operation of the facility.

[0012] Thus, the flow rate sensor can be used for flow rate detection of an aspirating smoke detection system. The flow rate sensor can be an easy to manufacture sensor that can be easily implemented in any new or existing aspirating smoke detection system. This method can allow for a cheaper and easier to install flow rate sensor than previous methods.

[0013] In the following Detailed Description, reference is made to the accompanying drawings which form part of the present Detailed Description. The drawings show, by way of illustration, the manner in which one or more embodiments of the present disclosure may be practiced.

[0014] These embodiments are described in sufficient detail to enable one of ordinary skill in the art to practice one or more embodiments of the present disclosure. It is to be understood that other embodiments may be utilized and process, electrical and / or structural changes may be made without departing from the scope of the present disclosure.

[0015] It should be understood that the elements shown in the various embodiments herein may be added, exchanged, combined and / or eliminated to provide multiple additional embodiments of the present disclosure. The proportions and relative sizes of the elements provided in the drawings are intended to illustrate embodiments of the present disclosure and should not be limiting.

[0016] The figures herein follow the following numbering convention: one or more first digits correspond to the figure number, and the remaining digits identify the element or component in the figure. Similar elements or components between different figures can be identified by using similar numerals. For example, 108 may refer to Figure 1 Component "08" in, and similar components can be found in Figure 2 It is referred to as 208 in Chinese.

[0017] Figure 1 FIG. 1 is an aspirating smoke detection system 100 having a flow rate sensor 104 according to one or more embodiments of the present disclosure. Figure 1 As shown, system 100 may include a duct sampling network 102 , a flow rate sensor 104 , an aspirating smoke detector device 106 , and a blower 108 .

[0018] As described above, the system 100 may include a pipeline sampling network 102. As used herein, the term "pipeline sampling network" refers to a set of pipelines configured to obtain a sample of a gas at a sampling location and to convey the gas from the sampling location to a detector. For example, the pipeline sampling network 102 may be located at each sampling location (e.g., not shown in the figure for clarity). Figure 1 The gas is sampled at a location (shown in the figure to avoid obscuring the embodiments of the present disclosure) and delivered to an aspirating smoke detector device 106 for analysis. The duct sampling network 102 may include various sampling ports located throughout the duct sampling network 102. As used herein, the term "port" refers to an orifice in a duct. The sampling ports may allow gas to flow from an area in the facility into the duct sampling network 102.

[0019] Although the pipeline sampling network 102 Figure 1 106. Although shown as a single pipe, the embodiments of the present disclosure are not limited thereto. For example, the pipe sampling network 102 may include more than one pipe. In addition, more than one pipe may be connected to the aspirating smoke detector device 106.

[0020] The system 100 may include a blower 108. As used herein, the term "blower" refers to a mechanical device for moving gas in a particular direction. For example, the blower 108 may be used to flow gas through the duct sampling network 102 and into the aspirating smoke detector device 106. In some cases, the blower 108 may include a duct housing with a fan that, when rotated, causes gas (e.g., such as air) to flow in a particular direction.

[0021] The system 100 also includes an aspirating smoke detector device 106 connected to the duct sampling network 102. As described above, the aspirating smoke detector device 106 can detect smoke particles within the gas sampled from the sampling location in the facility. The flow rate of the gas through the duct sampling network 102 and into the aspirating smoke detector device 106 can be determined by the flow rate sensor 104, as further described herein.

[0022] As described above, the system 100 includes a flow sensor 104. As used herein, the term "flow sensor" refers to a device that measures the flow rate of a fluid. The fluid can be, for example, a gas and / or a liquid. For example, the flow sensor 104 can measure the volume of a gas passing through a certain location per unit time.

[0023] As combined Figure 2 , Figure 3A and Figure 3B As further described, the flow rate sensor 104 may include a flow chamber, a coil, and a controller connected to the pipeline sampling network 102. The flow chamber may be connected to the pipeline sampling network 102 so that the gas flow flows through the flow chamber. In addition, the controller may be configured to receive a signal from the coil and determine the flow rate of the gas through the flow chamber based on the signal.

[0024] For example, in some examples, the coil is configured to physically oscillate in response to the flow of gas through the flow chamber. Thus, the controller is configured to determine the frequency of the signal, which frequency is associated with the physical oscillation of the coil; and determine the flow rate of the gas through the flow chamber based on the frequency, such as in combination with Figure 2 as further described.

[0025] Additionally, in some examples, the coil may be connected to a flexible base that is configured to deflect into the gas flow in the flow chamber in response to a voltage applied to the coil. Thus, the controller is configured to determine whether an amplitude associated with the voltage exceeds a threshold amplitude amount, and determine a flow rate of the gas through the flow chamber based on the voltage applied to the coil in response to the amplitude exceeding the threshold amplitude amount, such as in combination with Figure 3A and Figure 3B as further described.

[0026] Figure 2 2 is a top view of one example of a flow rate sensor 204 having a receiving coil 214 and a transmitting coil 216 according to one or more embodiments of the present disclosure. The flow rate sensor 204 may also include a flow chamber 210, a bluff body 212, and a controller 218.

[0027] As previously combined Figure 1As described, the flow rate sensor 204 may be connected to the pipeline sampling network. For example, the flow chamber 210 may be connected to the pipeline sampling network so that gas is allowed to flow from the pipeline sampling network and through the flow chamber 210 of the flow rate sensor 204 .

[0028] When gas enters the flow chamber 210 from the pipeline sampling network, the gas may encounter a bluff body 212. The bluff body 212 may be located inside the flow chamber 210 and may disrupt the flow of gas through the flow chamber 210. As used herein, the term "bluff body" refers to an object that causes a fluid flow to separate on the object due to its shape. For example, when the gas flows over the bluff body 212, the bluff body 212 separates the airflow, causing the boundary layer of the airflow to detach from the surface of the bluff body 212, forming a wake. In some examples, the bluff body 212 will cause the gas flowing through the flow chamber 210 to become turbulent in the flow chamber 210.

[0029] The flow rate sensor 204 may also include a receiving coil 214 located inside the flow chamber 210. The receiving coil 214 may be an electrical conductor in the shape of a coil, wherein the coil may generate a magnetic field when a current is applied. The receiving coil 214 may be located on a printed circuit board (PCB). For example, the PCB may be a polyimide PCB on which the receiving coil 214 is located.

[0030] like Figure 2 As shown, the receiving coil 214 may be located downstream of the bluff body 212 in the flow chamber 210. Therefore, the receiving coil 214 (e.g., PCB) may physically oscillate in response to the flow of the gas acting on the receiving coil 214. For example, when the gas flows through the flow chamber 210, the disturbed flow (e.g., turbulence) of the gas after interacting with the bluff body 212 may physically act on the receiving coil 214 (e.g., apply forces of varying magnitude thereto). Therefore, the receiving coil 214 may oscillate.

[0031] In response to the physical oscillation, the receiving coil 214 may generate a signal. The signal may be, for example, an amplitude modulated signal.

[0032] The flow rate sensor 204 may also include a transmitting coil 216. Figure 2 As shown, a transmitter coil 216 may also be located downstream of the bluff body 212. The transmitter coil 216 may be located outside of the flow chamber 210 and at the same location downstream of the bluff body 212 as the receiver coil 214.

[0033] Although the transmitting coil 216 is Figure 2 210, but the embodiments of the present disclosure are not limited thereto. For example, the transmitting coil 216 may be located inside the flow chamber 210, integrated within the body of the flow chamber 210, and so on.

[0034] The transmitting coil 216 may be an electromagnet located on the PCB. For example, the transmitting coil 216 may be a magnet, wherein a magnetic field is generated by the transmitting coil 216 when current passes through a coil surrounding the magnet.

[0035] like Figure 2 As shown, the receiving coil 214 and the transmitting coil 216 may be electrically connected to the controller 218. Thus, the receiving coil 214 and the transmitting coil 216 may transmit signals to the controller 218 and / or receive signals from the controller.

[0036] Controller 218 may cause an oscillating signal to be applied to transmit coil 216. Such an oscillating signal may cause receive coil 214 to generate a signal in response to physical oscillations of receive coil 214 (e.g., physical oscillations experienced by receive coil 214 due to disturbed airflow through flow chamber 210 caused by bluff body 212).

[0037] The signal generated by the receive coil 214 in response to the physical oscillation of the receive coil 214 may be transmitted to the controller 218. Thus, the controller 218 may determine the frequency of the signal generated by the receive coil 214. To determine the frequency, the controller 218 may demodulate the signal generated by the receive coil 214.

[0038] Once the controller 218 determines the frequency of the signal generated by the receiving coil 214, the controller 218 may determine the flow rate of the gas through the flow chamber 210 based on the frequency of the signal. For example, the controller 218 may include a memory (e.g., not shown here for clarity). Figure 2 , so as not to obscure embodiments of the present disclosure). The memory may include a lookup table stored therein. Thus, the controller 218 may determine the flow rate by comparing the frequency of the signal to a plurality of frequencies included in the lookup table and determining the flow rate to be a specific flow rate from the lookup table associated with a specific frequency based on the frequency matching a specific frequency in the lookup table.

[0039] For example, the lookup table may include a frequency of 100 Hertz (Hz) and an associated flow rate of 10 liters per minute (L / m), and a frequency of 150 Hz and an associated flow rate of 15 L / m. In response to the controller 218 determining that the frequency is 400 Hz, the controller 218 may compare the determined frequency (e.g., 400 Hz) to a plurality of frequencies (e.g., 400 Hz, 500 Hz, etc.) included in the lookup table, and determine the flow rate to be 10 L / m based on the determined frequency (e.g., 400 Hz) matching one of the plurality of frequencies in the lookup table (e.g., 400 Hz).

[0040] In some examples, the determined frequency may not exactly match those of the multiple frequencies in the lookup table. For example, the determined frequency may be 412 Hz. In some examples, the controller 218 may determine the frequency (e.g., 400 Hz) of the multiple frequencies in the lookup table that is closest to the determined frequency (e.g., 412 Hz) and determine the flow rate to be 10 L / m.

[0041] Furthermore, in some examples, the closest frequency may not produce the desired and / or required accuracy in determining the flow rate. In some examples, the controller 218 may interpolate between those frequencies in the multiple frequencies in the lookup table to determine the precise flow rate. For example, the determined frequency may be 412 Hz, and the controller 218 may interpolate using the two frequencies (e.g., 400 Hz and 500 Hz) in the multiple frequencies that are closest to the determined frequency to determine the flow rate associated with the 412 Hz frequency as approximately 10.6 L / m.

[0042] Figure 3A 3 is a top view of one example of a flow rate sensor 305 having a magnet 320 and a sensing coil 317 in a first position according to one or more embodiments of the present disclosure. The flow rate sensor 305 may also include a flow chamber 310, an inner surface 311 of the flow chamber 310, and a controller 318.

[0043] Similar to Figure 2 , the flow rate sensor 305 may be connected to the pipeline sampling network. For example, the flow chamber 310 may be connected to the pipeline sampling network so that gas is allowed to flow from the pipeline sampling network and through the flow chamber 310 of the flow rate sensor 305 .

[0044] The flow rate sensor 305 may include a magnet 320. The magnet 320 may be an object that generates a magnetic field.

[0045] The flow rate sensor 305 may also include a sensing coil 317 having a flexible base 315. The sensing coil 317 having a flexible base 315 may be located inside the flow chamber 310. The sensing coil 317 may be an electrical conductor in the shape of a coil, wherein the coil may generate a magnetic field when a current is applied. The flexible base 315 may be a flexible PCB, and the sensing coil 317 may be located on the flexible PCB. The flexible PCB may be a polyimide flat flexible PCB.

[0046] like Figure 3AAs shown, the sensing coil 317 with the flexible base 315 may be located at a first position. In the first position, the flexible base 315 may be located near the inner surface 311 of the flow chamber 310. In the first position, the sensing coil 317 and the flexible base 315 do not substantially interact with the flow of gas through the flow chamber 310 because their directional orientation is substantially similar to the flow direction of the gas through the flow chamber 310. That is, the orientation of the sensing coil 317 and the flexible base 315 in the first position is substantially parallel to the flow direction of the gas through the flow chamber 310.

[0047] like Figure 3A As shown, the sensing coil 317 with the flexible base 315 is located inside the flow chamber 310, and the magnet 320 is located outside the flow chamber 310. However, the embodiments of the present disclosure are not limited thereto. For example, the magnet 320 can be located inside the flow chamber 310, integrated in the body of the flow chamber 310, and so on.

[0048] 3, the sensing coil 317 and the magnet 320 may be electrically connected to the controller 318. Thus, the sensing coil 317 and the magnet 320 may transmit signals to the controller 318 and / or receive signals from the controller.

[0049] For example, the controller 318 may cause a direct current (DC) voltage to be applied to the sensing coil 317. The sensing coil 317 may accordingly receive a DC voltage from the controller 318 for controlling the displacement of the coil relative to the magnet. In addition, in addition to the DC voltage applied to the sensing coil 317, there may also be an AC voltage, which may provide a mechanism for detecting the displacement of the coil relative to the magnet. This mechanism for measuring the inductance of the coil may indicate the proximity of a metal component to the magnet.

[0050] To detect the aforementioned inductance, the signal from the controller 318 may be an oscillating AC voltage signal having high impedance and high frequency. For example, the applicable AC voltage may have an impedance of 100 ohms, a frequency of 10 MHz, and the like.

[0051] Magnet 320 may deflect sensing coil 317 with flexible base 315 from a first position to a second position due to application of a DC voltage to sensing coil 317. In the second position, receiving coil may more fully interact with the flow of gas through flow chamber 310, allowing the flow rate of gas through flow chamber 310 to be determined, such as in combination with Figure 3B as further described.

[0052] Figure 3B3 is a top view of one example of a flow rate sensor 305 having a magnet 320 and a sensing coil 317 in a second position according to one or more embodiments of the present disclosure. The flow rate sensor 305 may also include a flow chamber 310, an inner surface 311 of the flow chamber 310, and a controller 318.

[0053] As described above, due to the application of a DC voltage to the sensing coil 317, the magnet 320 can cause the sensing coil 317 having the flexible base 315 to move from a first position (e.g., as previously described in Figure 3A ) to a second position (e.g., as shown in Figure 3B When the sensing coil 317 with the flexible base 315 is in the second position, the sensing coil 317 with the flexible base 315 extends from the inner surface 311 of the flow chamber 310 and enters the airflow through the flow chamber 310. Applying a DC voltage to the sensing coil 317 causes the sensing coil 317 to be repelled away from the magnet 320 due to its opposite magnetic properties to the magnet 320.

[0054] As discussed, applying a DC voltage to the sensing coil 317 may cause the sensing coil 317 to extend a certain distance (e.g., away from the inner surface 311) into the gas flow. At the same time, when the receiving coil extends into the gas flow in the flow chamber 310, the gas flowing through the flow chamber 310 may exert a force on the sensing coil 317. For example, the orientation of the sensing coil 317 and the flexible base 315 in the second position is no longer substantially parallel to the flow direction of the gas through the flow chamber 310 as in the first position; instead, the sensing coil 317 and the flexible base 315 extend into the flow direction of the gas, and the gas impacts the sensing coil 317 and the flexible base 315, thereby providing a force that attempts to push the sensing coil 317 and the flexible base 315 back to the first position (e.g., but the force is offset by the magnetic reaction force from the magnet 320). Thus, the DC voltage applied to sensing coil 317 may be related to the amount of force required to move sensing coil 317 with flexible base 315 to the second position, and therefore, the flow rate of gas through flow chamber 310 may be inferred, as further described herein.

[0055] As previously described, the controller 318 may measure the amplitude of the AC voltage applied at the sensing coil 317. The predetermined amplitude threshold may be known such that when the amplitude measured at the sensing coil 317 reaches and / or exceeds the threshold, the controller 318 determines that the sensing coil 317 with the flexible base 315 is in the second position.

[0056] Thus, the controller 318 can determine whether the measured amplitude of the AC voltage associated with the DC voltage exceeds a threshold amplitude amount when the flexible base 315 is in the second position. Thus, the controller 318 can determine the flow rate of the gas through the flow chamber 310 based on the DC voltage in response to the amplitude exceeding the threshold amplitude amount, as further described herein.

[0057] Once the controller 318 has determined that the measured amplitude exceeds the threshold amplitude amount, the controller 318 may determine the flow rate of the gas through the flow chamber 310 based on the DC voltage applied to the sensing coil 317. For example, the controller 318 may include a memory (e.g., not shown here for clarity). Figure 3B , so as not to obscure the embodiments of the present disclosure). The memory may include a lookup table stored therein. Thus, the controller 318 may determine the flow rate by comparing the applied DC voltage to a plurality of DC voltages included in the lookup table and determining the flow rate to be a specific flow rate from the lookup table associated with a specific DC voltage based on the DC voltage matching a specific DC voltage in the lookup table.

[0058] For example, the lookup table may include a DC voltage of 2 volts (V) and an associated flow rate of 10 liters per minute (L / m), and a voltage of 3 V and an associated flow rate of 15 L / m. In response to the controller 318 determining that the applied DC voltage is 2 V, the controller 318 may compare the applied DC voltage (e.g., 2 V) to a plurality of DC voltages (e.g., 2 V, 3 V, etc.) included in the lookup table, and determine the flow rate to be 10 L / m based on the applied DC voltage (e.g., 2 V) matching a DC voltage (e.g., 2 V) among the plurality of DC voltages in the lookup table.

[0059] In some examples, the applied DC voltage may not completely match those of the plurality of DC voltages in the lookup table. For example, the applied DC voltage may be 2.2 V. In some examples, the controller 318 may determine a DC voltage (e.g., 2 V) that is closest to the applied DC voltage (e.g., 2.2 V) among the plurality of DC voltages in the lookup table and determine the flow rate to be 10 L / m.

[0060] Furthermore, in some examples, the closest frequency may not produce the desired and / or required accuracy in determining the flow rate. In some examples, the controller 318 may interpolate between those DC voltages in the multiple DC voltages in the lookup table to determine the precise flow rate. For example, the applied DC voltage may be 2.4V, and the controller 318 may interpolate using the two DC voltages (e.g., 2V and 3V) that are closest to the applied DC voltage among the multiple frequencies to determine the flow rate associated with the applied 2.4V DC voltage to be approximately 12L / m.

[0061] As described above, the resulting amplitude of the DC voltage applied to the sensing coil 317 may be indicative of the amount of force required to deflect and hold the sensing coil 317 with the flexible base 315 in the gas flow, and thus, the flow rate may be inferred from the DC voltage applied to the sensing coil 317. Thus, if the flow rate of gas through the flow chamber 310 increases, additional force will be required to hold the sensing coil 317 with the flexible base 315 in the second position (e.g., in the gas flow), and thus, the DC voltage applied to the sensing coil 317 will have to be increased.

[0062] Thus, if the flow rate increases, the amplitude will no longer exceed the threshold amplitude amount. Thus, in response to the amplitude not exceeding the threshold amplitude amount, the controller 318 may adjust the DC voltage applied to the sensing coil 317 to (e.g., increase the DC voltage to) a corrected DC voltage at which the measured amplitude exceeds the threshold amplitude amount. Using the lookup table, the controller 318 may then use the corrected DC voltage to determine the flow rate. Thus, this method may be used to determine the flow rate of gas through the flow chamber 310 even if the flow rate changes.

[0063] According to the present disclosure, flow rate detection for an aspirating smoke detection system may allow a flow rate sensor to be used for flow rate detection. The flow rate sensor may be easily manufactured and implemented in new and / or existing aspirating smoke detection systems. This approach may allow for a flow rate sensor that is cheaper and easier to install than previous approaches.

[0064] Figure 4 4 is a controller 402 for flow rate detection of an aspirating smoke detection system according to one or more embodiments of the present disclosure. Figure 4 As shown, the controller 402 may include a memory 442 and a processor 440 to perform flow rate detection for an aspirating smoke detection system according to the present disclosure.

[0065] The memory 442 may be any type of storage medium that can be accessed by the processor 440 to perform various examples of the present disclosure. For example, the memory 442 may be a non-transitory computer-readable medium having computer-readable instructions (e.g., computer program instructions) stored thereon that can be executed by the processor 440 for flow rate detection for an aspirating smoke detection system according to the present disclosure. The computer-readable instructions can be executed by the processor 440 to redundantly perform flow rate detection for an aspirating smoke detection system.

[0066] The memory 442 may be a volatile memory or a non-volatile memory. The memory 442 may also be a removable (e.g., portable) memory or a non-removable (e.g., internal) memory. For example, the memory 442 may be a random access memory (RAM) (e.g., a dynamic random access memory (DRAM) and / or a phase change random access memory (PCRAM)), a read-only memory (ROM) (e.g., an electrically erasable programmable read-only memory (EEPROM) and / or a compact disc read-only memory (CD-ROM)), a flash memory, a laser disc, a digital versatile disc (DVD) or other optical storage device and / or a magnetic medium (such as a cassette, a tape, or a disk), and other types of memory.

[0067] In addition, although the memory 442 is shown as being located within the controller 402, the embodiments of the present disclosure are not limited thereto. For example, the memory 442 may also be located within another computing resource (e.g., enabling computer readable instructions to be downloaded via the Internet or another wired or wireless connection).

[0068] Although specific implementations have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same technique may be substituted for the specific implementations shown. This disclosure is intended to cover any and all modifications or variations of various implementations of the present disclosure.

[0069] It should be understood that the above description is given in an illustrative and not limiting manner.By reading the above description, combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art.

[0070] The scope of the various embodiments of the present disclosure includes any other applications using the above-described structures and methods.The scope of the various embodiments of the present disclosure should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0071] In the above detailed description, various features are grouped together in the exemplary embodiments shown in the drawings for the purpose of simplifying the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the present disclosure require more features than are expressly recited in each claim.

[0072] Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment.Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

1. A flow rate sensor (104, 204, 305) for an aspirating smoke detection system (100), the flow rate sensor comprising: a flow chamber (210, 310) configured to allow a gas to flow through the flow chamber (210, 310); a bluff body (212) located within the flow chamber (210, 310) and configured to disrupt the flow of the gas through the flow chamber (210, 310); A receiving coil (214), the receiving coil being located inside the flow chamber (210, 310), wherein: The receiving coil (214) is configured to physically oscillate in response to the flow of the gas acting on the receiving coil (214); and In response to the physical oscillation, the receiving coil (214) is configured to generate a signal; Memory (442); and a processor (440) configured to execute executable instructions stored in the memory (442) to: determining a frequency of the signal generated by the receiving coil (214); and A flow rate of the gas through the flow chamber (210, 310) is determined based on the frequency of the signal.

2. The flow rate sensor (104, 204, 305) of claim 1, wherein the processor (440) is configured to determine the flow rate by comparing the frequency of the signal with a plurality of frequencies included in a lookup table.

3. A flow rate sensor (104, 204, 305) according to claim 2, wherein the processor (440) is configured to determine the flow rate by determining the flow rate as a specific flow rate from the lookup table associated with the specific frequency based on matching the frequency with a specific frequency among the multiple frequencies included in the lookup table.

4. The flow rate sensor (104, 204, 305) according to claim 1, wherein the flow rate sensor (104, 204, 305) further comprises a transmitting coil (216).

5. The flow rate sensor (104, 204, 305) according to claim 4, wherein the processor (440) is configured to cause an oscillating signal to be applied to the transmitting coil (216) so that the receiving coil (214) generates the signal in response to the physical oscillation of the receiving coil (214).

6. The flow rate sensor (104, 204, 305) of claim 4, wherein the transmitting coil (216) is an electromagnet located on a printed circuit board.

7. The flow rate sensor (104, 204, 305) according to claim 1, wherein the signal generated by the receiving coil (214) is an amplitude modulated signal.

8. The flow rate sensor (104, 204, 305) of claim 1, wherein the processor (440) is configured to demodulate the signal generated by the receiving coil (214) to determine the frequency.

9. The flow rate sensor (104, 204, 305) of claim 1, wherein the bluff body (212) is configured to cause the gas flowing through the flow chamber (210, 310) to become turbulent in the flow chamber (210, 310).

10. The flow rate sensor (104, 204, 305) of claim 1, wherein the receiving coil (214) is located downstream of the bluff body (212) in the flow chamber (210, 310).

Images