WO2020028339A1 - Pressure sensor systems and methods for building envelope testing - Google Patents

Abstract

Systems and methods for providing pressure sensor systems to collect differential air pressure readings during a building envelope test. The systems and methods utilize high accuracy absolute pressure sensors, which enables a pressure sensor system to operate using no tubes across a building envelope. The systems may utilize large capacity batteries and wireless technology to allow both the reading of a plurality of sensor devices by a central base station without installing wiring as well as reading the sensor devices practically simultaneously to greatly increase real-time accuracy of the test results. The pressure sensor system may also include an optional weather station which also communicates with the base station via a wired or wireless connection to include various weather parameters, such as local outside absolute pressure, temperature, humidity, and wind speed readings in order to correct readings taken from the stand-alone sensor devices.

Description

PRESSURE SENSOR SYSTEMS AND METHODS FOR BUILDING ENVELOPE

TESTING

BACKGROUND

Technical Field

The present disclosure generally relates to building envelope testing, and more particularly, to pressure sensor systems and methods for building envelope testing.

Description of the Related Art

Environmental testing of buildings to detect excessive air leakage is now mandated in many areas of the country and of the world. This is done to allay inefficiencies and energy wastage, and is performed in accordance with standards such as American Society for Testing and Materials (ASTM) Standard E779 10, among others. This requires the ability to accurately measure the air pressure differential between the inside of a building and the outside (“across the envelope”) during either pressurization or depressurization to determine the exact air leakage and effective leakage area. Until now, this has meant using high-accuracy low-range differential pressure (dP) sensors located in various (mandated) areas in the building under test. Using sensors such as these comes with several disadvantages, such as: the differential pressure sensor requires sampling the pressure on both sides of the envelope at once, meaning a tube has to be manually run through the envelope to the sensor; the sensor must be read either manually at the sensor or remotely via networked connection; and reading the sensors manually necessarily creates a time lag between the start and finish of a given sample time, which reduces accuracy in the dynamic environment of changing wind conditions and temperatures. BRIEF SUMMARY

A pressure sensor system may be summarized as including: a plurality of pressure sensor devices that are each positionable in an interior or exterior of a building under test, each of the pressure sensor devices including: an absolute pressure sensor; a sensor device communications interface; and a sensor device controller operatively coupled to the absolute pressure sensor and the sensor device communications interface; and a base station including: a base station communications interface; and a base station controller operatively coupled to the base station communications interface, in operation, the controller: during a first time period, receives sensor data from the plurality of pressure sensor devices via the base station communications interface, at least one of the pressure sensor devices positioned at the interior of the building and at least one of the pressure sensor devices positioned at the exterior of the building; for each of the plurality of pressure sensor devices, determines an offset based at least in part on the received sensor data; during a second time period subsequent to the first time period in which a test is performed, receives sensor data from the plurality of pressure sensor devices via the base station communications interface; and determines at least one differential pressure based at least in part on the sensor data received during the second time period and the determined offsets for the plurality of sensors.

The sensor device communications interface and the base station communications interface may include wireless communications interfaces. At least one of the plurality of pressure sensor devices may include a temperature sensor. At least one of the plurality of pressure sensor devices may include a rechargeable battery operative to provide power to the components of the pressure sensor device. The base station controller may receive sensor data from a weather station, and may determine the at least one differential pressure based at least in part on the sensor data received from the weather station. The sensor data received from the weather station may include sensor data indicative of at least one of local outside absolute pressure, temperature, humidity, or wind speed. The base station controller may adaptively filter and estimate the absolute pressure reported by each of the sensor devices to determine the offset. The sensor device controller may transmit frames of filtered digitized absolute pressure and temperature data to the base station. The base station controller may timestamp the sensor data received from the plurality of pressure sensor devices. The base station controller may autonomously determine which of the plurality of pressure sensor devices are positioned at the interior of the building under test, and which of the plurality of pressure sensor devices are positioned at the exterior of the building under test. The base station controller may determine the elevation of the building under test based at least in part on the received sensor data.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not necessarily intended to convey any information regarding the actual shape of the particular elements, and may have been solely selected for ease of recognition in the drawings.

Figure l is a schematic diagram of a networked environment in which a pressure sensor system may be implemented, according to one non-limiting illustrated implementation.

Figure 2 is a block diagram showing the various components of a pressure sensor device and a base station of the pressure sensor system of Figure 1, according to one non-limiting illustrated implementation.

Figure 3 is a schematic diagram of a pressure sensor device, according to one non-limiting illustrated implementation.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed implementations. However, one skilled in the relevant art will recognize that implementations may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with computer systems, server computers, and/or communications networks have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the

implementations. Unless the context requires otherwise, throughout the specification and claims that follow, the word“comprising” is synonymous with“including,” and is inclusive or open-ended (i.e., does not exclude additional, unrecited elements or method acts).

Reference throughout this specification to“one implementation” or“an implementation” means that a particular feature, structure or characteristic described in connection with the implementation is included in at least one implementation. Thus, the appearances of the phrases“in one implementation” or“in an implementation” in various places throughout this specification are not necessarily all referring to the same implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more implementations.

As used in this specification and the appended claims, the singular forms “a,”“an,” and“the” include plural referents unless the context clearly dictates otherwise. It should also be noted that the term“or” is generally employed in its sense including“and/or” unless the context clearly dictates otherwise.

The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the implementations.

One or more implementations of the present disclosure are directed to systems and methods that alleviate many of the disadvantages of using differential pressure sensors to collect differential air pressure readings during a building envelope test. The systems and methods disclosed herein utilize high accuracy absolute pressure sensors, which enables a system to operate without use of tubes at all. In at least some implementations, the systems may utilize large capacity batteries and wireless technology to allow both the reading of all sensors without installing wiring as well as reading the sensors practically simultaneously (e.g., by a central base station) to greatly increase real-time accuracy of the test results.

In at least some implementations, a wireless remote sensor system is provided that measures differential pressure occurring across the test envelope or thermal/pressure boundary. The system may measure and monitor interior pressures verses exterior atmospheric pressure, which occurs in a dynamic environment (e.g., during performance of a multi-point linear regression test under positive and negative pressures). By utilizing wireless sensors, the system is able to instantaneously measure, compensate, and data-log effects caused by wind, temperature (e.g., Stack Effect), test isolation failures, etc. In at least some implementations, the sensor system uses high resolution sensor technology to process and obtain precision differential pressure comparison through relative accuracy, not direct accuracy of absolute pressure sensors. For example, the system may establish a baseline or offset for each sensor device, and then utilizes the relative changes across each sensor device to derive a final comparison of differential pressure. This is a radical departure from standard approaches to differential pressure measurement. By harvesting these data inputs in conjunction with complex algorithmic analysis, the system is able to create a pressure topography in an unlimited number of locations across the interior/exterior of the test envelope in a wireless manner, which provides significant accuracy, efficiency, and precision benefits.

Figure 1 shows an example environment for a pressure sensor system 100. In the illustrated example, the environment includes a building 106 under test that has an interior 108 and an exterior 110. The system 100 includes a plurality of mobile stand-alone sensor devices l02a-l02g (collectively, sensor devices 102) and a main base station 104. Each of the sensor devices 102 may include a microcontroller (or other processor-based device) with wireless (e.g., Wi-Fi®) capability to read pressure and/or temperature transducers of the sensor device 102 and report the temperature and absolute pressure to the base station 104 via the wireless or wired connection. The system 100 may also include an optional weather station 116 which also communicates with the base station 104 via a wired or wireless connection to include various weather parameters, such as local outside absolute pressure, temperature, humidity, and wind speed readings in order to correct the readings taken with the stand-alone sensors 102.

As shown in Figure 1, the base station 104 may communicate with other processor-based systems or services 114 over one or more wired and/or wireless networks 112. As an example, the base station 104 may connect to a wireless network 112, such as a cellular network, which may communicate with a wide area network (e.g., Internet) via a gateway. Similarly, the base station 104 may communicate with an access point which provides communication access to the wide area network. In some implementations, the base station 104 may also establish peer-to-peer communications with other devices by use of one or more wired and/or wireless communication subsystems. Further, in at least some implementations, the sensor devices 102 may be operative to communicate with remote devices (e.g., system or service 114), such that a dedicated base station 104 is not required. Other communication protocols and topologies may also be implemented.

In some implementations, the base station 104 or the sensor devices 102 may communicate with the one or more services 114 over the one or more wired and/or wireless networks 112. For example, the one or more services 114 may provide sensor processing services to implement some or all of the processing required for testing of the building 106. Thus, it should be appreciated that the functionality disclosed herein may be provided on a single system or may be distributed across multiple systems in any combination.

At present, absolute pressure transducers with the accuracy required to measure pressure differences between two transducers of 1 Pascal (Pa) at standard atmospheric conditions of around 101,000 Pa are prohibitively expensive, which makes them impractical for widespread use. Accordingly, in at least some implementations, the sensor devices 102 disclosed herein may utilize absolute pressure transducers with “relative accuracy” of 1 Pa, for example.“Relative accuracy” is the accuracy of tracking pressure changes from one reading to the next over a relatively short duration (e.g., 24 hours).

As shown in Figure 1, for a building 106 under test, the stand-alone sensor devices 102 are strategically placed both inside 108 and outside 110 of the building envelope. In the example shown, sensor devices 102a- 102c are positioned inside 108 the building 106 under test, and sensors l02d-l02g are positioned outside 110 of the building. It should be appreciated that in practice, more or fewer sensor devices 102 may be positioned inside 108 or outside 110 the building 106 under test. Wireless communication may be established between each sensor device 102 and the base station 104. Additionally or alternatively, communications may be established via a wireless mesh with other sensor devices 102 which can communicate with the base station 104 or another device located proximate the sensors or remote therefrom. In at least some implementations, at the start of a testing cycle, the base station 104 may adaptively filter and estimate the absolute pressure reported by each of the stand-alone sensor devices 102 to determine a baseline or“offset” for each of the sensor devices. During the test, the building is pressurized (or depressurized) to standard differential pressure values mandated by the standard which governs the particular test protocol in use, and the differential pressure is held steady for a mandated time. During this time, the base station 104 reads the new reported absolute pressure from each of the stand-alone sensor devices 102 and calculates the difference between the new reading and the determined offset, and the change between one side (e.g., inside 108) of the envelope of the building 106 and the other side (e.g., outside 110). This reading may be done by the base station 104 via wireless connections, such that all sensor devices 102 are read at practically the same time. Data are recorded at the base station 104, and calculations are performed to determine whether the test is valid and whether the building 106 is in compliance with applicable codes. The ability to station the sensor devices 102 at various locations and obtain real-time readings also allows for determining where to look for air leaks, should this become necessary during testing.

The system 100 advantageously provides the ability to closely and accurately track changes to each stand-alone sensor device 102, as well as the ability to compare readings in real-time along with historical introspection from continuously logging all samples. For example, if the interior 108 pressure changes by 50 Pa, but the outside 110 pressure changes by 10 Pa due to a wind gust, the instantaneous actual differential pressure of 40 Pa is readily apparent. As noted above, in at least some implementations, the system 100 may utilize wireless connectivity to reduce the labor and costs required to create a wired network of sensor devices 102, and to eliminate the required envelope penetrations required with wires, or alternatively, referencing tubing for conventional digital manometers.

In at least some implementations, the deployed sensor devices 102 periodically transmit frames of filtered digitized absolute pressure and temperature data to the base station 104, which includes logic for processing the data. This base station 104 may timestamp all incoming samples with the same clock governing all other sampling time references, and may track any dropped frames to allow for proper time and frequency-domain analysis of pressure data. Data may be calibrated and corrected based on the reported temperature data.

Utilizing timestamped data also allows for comparison to PID-controlled timestamped conventional manometer data responsible for pressurizing and

depressurizing the building 106 envelope, both in real-time, and/or at any previous time during the test. In at least some implementations, the system 100 may automatically determine which of the deployed pressure sensor devices 102 are positioned inside 108 the building 106 envelope, and which are outside 110 by comparing to manometer data (e.g., to the nearest second) during pressurization and depressurization events, for example. These flags may be tracked throughout the test, and may automatically provide temperature and differential pressure topography inside 108 and outside 110 the building 106 envelope. These data may be used to compute average temperatures, E779-l0-style temperature contrast corrections of pressure data to facilitate in standard reference leakiness computations.

Assuming a Gaussian distribution of absolute pressure accuracy, sensor devices 102 determined to be outside 110 the building 106 envelope may be averaged to correct for any absolute pressure biases to estimate barometric pressure, and then the base station 104 (or other local or remote processing unit) may convert this to an estimation of elevation above sea level. Thus, the system 100 can usefully estimate the elevation of the building 106 in the absence of a weather station 116 within the accuracy required by various standards (e.g., E779-10).

The base station 104 may track data continuously, monitoring any sensor startup transients, and may supply an indicator to an operator about the readiness of all tracked sensor devices 102. Other data quality statistical metrics estimate sensor errors to only compute differential pressure data with valid samples and warn an operator about any potential issues.

After all deployed sensor devices 102 are flagged as ready, then a timestamped pressurization or depressurization start/stop event may automatically track and filter individual sensor values for some duration directly before the event to estimate individual sensor absolute offsets to adaptively correct and subtract interior 108 and exterior 110 pressure data to yield differential pressure data without supervised calibration by an operator.

The base station may also track any sensor drift to adaptively estimate sensor bias for the entire duration of the test to ensure biases, and hence differential pressure calculations, are accurate without operator intervention.

At least two types of dynamic differential pressure calculations are possible using the system 100. First, the system 100 may compare a corrected interior pressure sample to another corrected exterior pressure. Second, the system 100 may compare a corrected interior pressure sample to an aggregation of corrected exterior pressure samples for a more general differential pressure estimation. The former can provide individual building envelope diagnostics such as leeward vs. windward building faces compared to a smoothed exterior topography without lower noise.

In at least some implementations, the sensor devices 102 may be renamed with aliases to provide cues for deployed sensor location to the operator or base station 104. If the sensor devices 102 are named or labeled according to relative position around the building 106 envelope, an automated display of the spatial topography may be provided (e.g., via a display of the base station).

In at least some implementations, readings from each of the sensor devices 102 may be compared to each other and/or to other conventional manometer data to identify a nominal differential pressure per second, and the system 100 may automatically flag and warn when a sensor device 102 is outside of a variable tolerance. For example, the E779-10 standard requires that the pressure topography varies no more than 10 % during a (de-)pressurization test.

Figure 2 is a system diagram that illustrates various components of the sensor devices 102 and the base station 104 of the pressure sensor system 100. As discussed above, the base station 104 communicates with the sensor device 102 to periodically collect sensor data therefrom. Although Figure 2 illustrates a single sensor device 102 as communicating with the base station 104, as discussed above, in practice the base station 104 may also communicate with a plurality of sensor devices 102.

One or more special-purpose computing systems may be used to implement the base station 104. Accordingly, various embodiments described herein may be implemented in software, hardware, firmware, or in some combination thereof. Base station 104 may include memory 220, a display 227 (e.g., touchscreen, monitor) one or more central processing units (CPUs) 228, I/O interfaces 232, other computer- readable media 230, and network connections 234. The base station 104 may be in the form of a laptop computer, desktop computer, tablet computer, smartphone, server, cloud-based system, etc.

Memory 220 may include one or more various types of non-volatile and/or volatile storage technologies. Examples of memory 220 may include, but are not limited to, flash memory, hard disk drives, optical drives, solid-state drives, various types of random access memory (RAM), various types of read-only memory (ROM), other computer-readable storage media (also referred to as processor-readable storage media), or the like, or any combination thereof.

Memory 220 is utilized to store information, including computer- readable instructions that are utilized by CPU 228 to perform actions and embodiments described herein. For example, memory 220 may have stored thereon a sensor data processing system 222 that implements the functionality disclosed herein, and a sensor data database 224 that stores sensor data received from the sensor devices 102.

Memory 220 may also store other programs and data, not illustrated, to perform other actions associated with the operation of base station 104. Other computer-readable media 230 may include other types of stationary or removable computer-readable media, such as removable flash drives, external hard drives, or the like.

Network connections 234 are configured to communicate with other computing devices, such as the sensor devices 102, systems or services 114, or other devices not illustrated in this figure. In various embodiments, the network connections 234 include wired or wireless transmitters and receivers (not illustrated) to send and receive data as described herein. For example, the network connections 234 may include wireless communication subsystems designed to operate over a global system for mobile communications (GSM) network, a GPRS network, an enhanced data GSM environment (EDGE) network, 802.x communication networks (e.g., Wi-Fi®), code division multiple access (CDMA) networks, NFC networks, Bluetooth® networks, and/or Bluetooth® Low Energy (BLE) networks. Network connections 234 may additionally or alternatively include one or more wired communication connections (e.g., USB®, micro-USB®).

I/O interfaces 232 may include a keyboard, audio interfaces, video interfaces, or the like. The display 227, which may be considered part of the EO interfaces 232, may include a display interface that is utilized to present a graphical interface to an operator to see various types of information regarding the processed or unprocessed sensor data.

The sensor device 102 communicates various types of information (e.g., sensor data) with the base station 104 via a wireless or wired connection. One or more special-purpose computing systems may be used to implement sensor device 102. Accordingly, various embodiments described herein may be implemented in software, hardware, firmware, or in some combination thereof.

Sensor device 102 may include memory 250, one or more central processing units (CPUs) 262, display 258, EO interfaces 266, other computer-readable media 264, network connections 260, temperature sensor 268, pressure sensor 270, and a power source 272 (e.g., battery).

Memory 250 may include one or more various types of non-volatile and/or volatile storage technologies, similar to what is described above for memory 220. Memory 250 is utilized to store information, including computer readable instructions that are utilized by CPU 262 to perform actions. In some embodiments, memory 250 may have stored thereon a data reporting system 252. The data reporting system 252 includes one or more modules that perform various actions so that the sensor device 102 can communicate with the base station 104 to perform the functionality described herein. For example, the data reporting system 252 may from time-to-time (e.g., every second, every 10 seconds, every minute) transmit temperature data, pressure data, or other types of data to the base station 104. In some

embodiments, the data reporting system 252 may modify the functioning of the sensor device 102 based on commands or instructions received from the base station 104 or from another device via wired or wireless connection, such as to modify the particular data reporting functionality of the sensor device 102. Memory 250 may also store other programs 254 and other data 256 to perform other actions associated with the operation of sensor device 102.

Display 258 is configured to provide information or content to a display device for presentation to the user, such as readings of current or historical sensor data. In some embodiments, display 258 includes the display device, such as an LCD or LED display screen or other display device.

I/O interfaces 266 may include a keyboard, audio interfaces (e.g., a speaker for outputting sound-based SOS signals), other video or visual interfaces (e.g., a camera, camera-flash light, etc.), or the like. Network connections 260 are configured to communicate with other computing devices, such as base station 104 or other computing devices not illustrated in this figure. In various embodiments, the network connections 260 include wired or wireless transmitters and receivers (not illustrated) to send and receive data as described herein. For example, the network connections 260 may include wireless communication subsystems designed to operate over a global system for mobile communications (GSM) network, a GPRS network, an enhanced data GSM environment (EDGE) network, 802.x communication networks (e.g., Wi-Fi®), code division multiple access (CDMA) networks, NFC networks, Bluetooth® networks, and/or Bluetooth® Low Energy (BLE) networks. Network connections 234 may additionally or alternatively include one or more wired communication connections (e.g., USB®, micro-USB®). Other computer-readable media 264 may include other types of stationary or removable computer-readable media, such as removable flash drives, external hard drives, or the like.

Figure 3 is a schematic diagram of a pressure sensor device 300, according to one non-limiting illustrated implementation. The pressure sensor device 300 may be similar or identical to the sensor devices 102 discussed above. In the illustrated implementation, the pressure sensor device 300 includes a microcontroller 302 that is operatively coupled to a pressure and temperature sensor 304. The pressure sensor device 300 also includes a display 306, a battery 308, and a USB® port 310. In the illustrated example, the microcontroller 302 comprises an ESP8266 microcontroller produced by Espressif Systems. The microcontroller 302 is a low-cost Wi-Fi® enabled microchip with full TCP/IP stack and microcontroller capabilities. The pressure sensor 304 may be an ICPlOlxx type sensor available from InvenSense, for example, which provides accurate absolute pressure and temperature measurements. The battery 308 may be a rechargeable lithium ion polymer (LiPo) battery, for example, which is operative to power the sensor device 300 for an extended period of time. The display 306 may be a 128x128 pixel TFT LCD display available from Adafruit Industries, LLC, for example. It should be appreciated that the particular components discussed above are provide by way of example, and should not be considered as limiting the present disclosure.

In at least some implementations, the relative accuracy of the absolute pressure sensors may also be increased programmatically within the controller portion of each sensor device (e.g., devices 102 or 300) prior to transmitting the absolute pressure reading to a central processing portion of the system (e.g., wirelessly to the base station 104). This may be done individually for each sensor device as part of an initial calibration process, and may need to be re-performed if the pressure sensor is replaced. This may use either the method of programming in an offset value for the readings, as discussed above, or may take the form of performing statistical

manipulation of the readings to increase the accuracy of the reported readings.

Another implementation that may be used in at least some implementations to increase the accuracy of the reported readings is to use a low-range ultra-high-accuracy differential pressure sensor instead of an absolute pressure sensor.

In such implementations, at the start of any test, one inlet to the differential pressure sensor may be physically closed off from the environment, and the other inlet left open. As pressure in the building is changed during a test, the differential pressure sensor directly reads that change and report that number back to the base station, rather than the base station obtaining the absolute pressure at the start of the test and the absolute pressure at each test step, and finding the difference mathematically. In this case, the method of inferring the building envelope differential pressure by reading changes inside and changes outside and subtracting to find the envelope differential pressure remains unchanged, the only difference being how the difference within each sensor device is found. Although the disclosure references building envelope testing as a particular application for which the systems and methods of the present disclosure may be suitable, it should be appreciated that the functionality provided herein may be implemented in many other applications. As a non-limiting example, the systems and methods disclosed herein may be used in applications such as high accuracy aviation (avionics and global positioning systems (GPS)), specifically high accuracy altimeter functions. Other applications will be readily apparent to those skilled in the art.

In at least some implementations, a sensor wireless controller may be configured to be a“Wi-Fi relay” that may or may not include an actual sensor to act as a specialized Wi-Fi range extender. In some applications, a plurality of such wireless range extenders may communicate with local sensors and to other extender modules within range and relay sensor data to a central processor (e.g., base station) in real-time. In at least some implementations, the sensors of the present disclosure may support “Mesh Wi-Fi” in order to expand the available range between each individual sensor and the central processor or the Wi-Fi relay discussed above.

In at least some implementations, a wireless weather station may be provided that operates to provide real-time data on absolute atmospheric pressure, temperature, relative humidity, wind speed, etc. The wireless weather station may be communicatively coupled to the central processor to provide the data thereto.

Various other functionality may be provided by the software of the central processor, individual sensors, or both. For example, to further increase the accuracy or precision of the sensor readings, in at least some implementations the software may offset any steady bias between the actual and reported change of pressure, found during individual sensor calibration and unique to each sensor, in order to get the reported pressure change to more closely match a pressure standard traceable to the NIST. Additionally, the software may be operative to find the randomness of each reported reading within the sensors’ guaranteed accuracy and statistically find and apply the tolerance, accuracy, and confidence intervals for each sensor.

In at least some implementations, one or more sensors may be stationed around the outside of the building under test to reduce or eliminate the need for wind speed measurement. Since a purpose of wind speed measurement is to estimate the effect of wind speed on the offset of the actual differential air pressure measured on each face of the building under test, and since this configuration provides a direct measurement of that, in this configuration there is no need to calculate that effect from wind speed measurement since the actual difference between one side of a building and the other(s) is known. This“direct measurement” method may also extend to measuring the differential between the lower and upper levels of a building during a test caused by the change in temperature during the test (e.g., the stack effect). This may increase the accuracy of the overall building envelope test.

In some embodiments, the system may measure the different air flow rates at a single differential pressure level with varying wind speeds. Advantageously, through the application of simultaneous equations to the different flow rates and measured differential pressures, the flow rate through each building face, and therefore the equivalent leakage area, may be calculated and used to produce more accurate or precise measurements.

The foregoing detailed description has set forth various implementations of the devices and/or processes via the use of block diagrams, schematics, and examples. Insofar as such block diagrams, schematics, and examples contain one or more functions and/or operations, it will be understood by those skilled in the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one implementation, the present subject matter may be implemented via Application Specific Integrated Circuits (ASICs). However, those skilled in the art will recognize that the implementations disclosed herein, in whole or in part, can be equivalently implemented in standard integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more controllers (e.g., microcontrollers) as one or more programs running on one or more processors (e.g., microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of ordinary skill in the art in light of this disclosure. Those of skill in the art will recognize that many of the methods or algorithms set out herein may employ additional acts, may omit some acts, and/or may execute acts in a different order than specified.

In addition, those skilled in the art will appreciate that the mechanisms taught herein are capable of being distributed as a program product in a variety of forms, and that an illustrative implementation applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution.

Examples of signal bearing media include, but are not limited to, the following:

recordable type media such as floppy disks, hard disk drives, CD ROMs, digital tape, and computer memory.

The various implementations described above can be combined to provide further implementations. These and other changes can be made to the implementations in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific implementations disclosed in the specification and the claims, but should be construed to include all possible implementations along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.

U.S. Provisional Patent Application No. 62/712,054, filed July 30, 2018, to which the present application claims priority, is hereby incorporated herein by reference in its entirety.

Claims

1. A pressure sensor system, comprising:

a plurality of pressure sensor devices that are each positionable in an interior or exterior of a building under test, each of the pressure sensor devices comprising:

an absolute pressure sensor;

a sensor device communications interface; and

a sensor device controller operatively coupled to the absolute pressure sensor and the sensor device communications interface; and

a base station comprising:

a base station communications interface; and a base station controller operatively coupled to the base station communications interface, in operation, the controller:

during a first time period, receives sensor data from the plurality of pressure sensor devices via the base station communications interface, at least one of the pressure sensor devices positioned at the interior of the building and at least one of the pressure sensor devices positioned at the exterior of the building;

for each of the plurality of pressure sensor devices, determines an offset based at least in part on the received sensor data;

during a second time period subsequent to the first time period in which a test is performed, receives sensor data from the plurality of pressure sensor devices via the base station communications interface; and

determines at least one differential pressure based at least in part on the sensor data received during the second time period and the determined offsets for the plurality of sensors.

2. The pressure sensor system of claim 1 wherein the sensor device communications interface and the base station communications interface comprise wireless communications interfaces.

3. The pressure sensor system of claim 1 wherein at least one of the plurality of pressure sensor devices comprises a temperature sensor.

4. The pressure sensor system of claim 1 wherein at least one of the plurality of pressure sensor devices comprises a rechargeable battery operative to provide power to the components of the pressure sensor device.

5. The pressure sensor system of claim 1 wherein the base station controller receives sensor data from a weather station, and determines the at least one differential pressure based at least in part on the sensor data received from the weather station.

6. The pressure sensor system of claim 5 wherein the sensor data received from the weather station comprises sensor data indicative of at least one of local outside absolute pressure, temperature, humidity, or wind speed.

7. The pressure sensor system of claim 1 wherein the base station controller adaptively filters and estimates the absolute pressure reported by each of the sensor devices to determine the offset.

8. The pressure sensor system of claim 1 wherein the sensor device controller transmits frames of filtered digitized absolute pressure and temperature data to the base station.

9. The pressure sensor system of claim 1 wherein the base station controller timestamps the sensor data received from the plurality of pressure sensor devices.

10. The pressure sensor system of claim 1 wherein the base station controller autonomously determines which of the plurality of pressure sensor devices are positioned at the interior of the building under test, and which of the plurality of pressure sensor devices are positioned at the exterior of the building under test.

11. The pressure sensor system of claim 1 wherein the base station controller determines the elevation of the building under test based at least in part on the received sensor data.