Patent Description:
Acoustic emission sensors are typically used in known monitoring systems to monitor an operational status of a device (e.g., a valve or other process control device) to which an acoustic emission sensor is coupled. In some known examples, the acoustic emission sensor is monitored to determine whether the acoustic emission sensor is functioning properly and, as a result, whether measurements from the acoustic emission sensor are accurate. One known method of verifying this functionality is a pencil lead break test that involves a person (e.g., an operator or technician) breaking lead from a mechanical pencil adjacent the acoustic emission sensor. Another known test involves using piezoelectric sensors in a reciprocity mode. However, these known tests do not meet the reproducibility and/or practical implementation requirements needed to properly assess the acoustic emission sensor and can also cause an operator or technician to improperly assess the functionality of the acoustic emission sensor.

<CIT> discloses an apparatus for calibrating acoustic emission sensors. <CIT> discloses a method for standardizing acoustic emission signals <CIT> discloses a diagnostic apparatus using an acoustic emission sensor. <CIT> discloses a vibration-based damage detection system.

There is provided an acoustic test apparatus, an acoustic test method and a tangible medium comprising acoustic test instructions according to the appended claims.

The figures are not to scale. Instead, to clarify multiple layers and regions, the thickness of the layers may be enlarged in the drawings. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, means that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.

Methods and apparatus to verify operation of acoustic emission sensors are disclosed. Acoustic emission sensors are typically used to verify an operation and/or operational status of a device (e.g., a process control device). As a result, the functionality of the acoustic emission sensor is verified to ensure that data collected from the acoustic emission sensor is precise and/or accurate. Therefore, some known testing/monitoring systems utilize a lead break test. Other known testing/monitoring systems utilize multiple acoustic emission sensors and/or piezoelectric devices to verify operation of the acoustic emission sensor.

The examples disclosed herein provide an accurate and cost-effective way of characterizing an operating status or condition of an acoustic emissions sensor and/or a data chain associated with the acoustic emission sensor. In particular, the examples disclosed herein utilize an acoustic source (e.g., a DC motor, an asymmetric motor, a piezoelectric device, a resonator, a tuning fork, etc.) and/or an appropriate haptic device to generate an acoustic signal that is measured at the acoustic emissions sensor of interest. According to the present invention, the acoustic source includes a haptic motor. The measured signal is compared to a baseline (e.g., a baseline signal, a recorded baseline signal, etc.), which may include a threshold value and/or an expected waveform. The examples used herein utilize acoustic sources (e.g., simulated acoustic emission sources) such as motors, turning forks, resonators and/or other haptic devices, which are relatively inexpensive and uncomplicated to implement. The examples disclosed herein mount the acoustic source in a housing and/or enclosure to ensure reliable mechanical and acoustic coupling.

As used herein, the term "motor" may refer to a motor with an asymmetric counterweight or any appropriate haptic devices and/or vibrational devices that generate acoustic wave sources or vibrations. As used herein, the term "waveform" refers to any type of electrical signal, which may or may not be normalized (e.g., unitless).

<FIG> is a diagram of an acoustic test apparatus <NUM> that may be implemented to test an operational condition of an acoustic emission sensor <NUM>, which may be, for example, commercially available (e.g., a Vallen Systeme acoustic emission sensor). The example acoustic emission sensor <NUM> includes a housing <NUM> and a piezoelectric element <NUM> disposed in and/or at least partially surrounded by the housing <NUM>. The example acoustic emission sensor <NUM> also includes a wear plate <NUM> coupled to the housing <NUM>. The wear plate <NUM> of the illustrated example is at least partially surrounded by the housing <NUM> and protects (e.g., prevents damage to) the piezoelectric element <NUM>. In some examples, other components (e.g., an electrode, damping material, etc.) may also be disposed within the housing <NUM>. The acoustic test apparatus <NUM> also includes an example process control device <NUM>, which may be a valve, a pipe, or any other process control device. The acoustic emission sensor <NUM> is operatively coupled to a surface <NUM> of the process control device <NUM> via the wear plate <NUM>, and is disposed proximate the process control device <NUM> to create an acoustic path by facilitating propagation of acoustic signals to the acoustic emission sensor <NUM>. In the illustrated example of <FIG>, an acoustic source <NUM>, which is implemented as a motor (e.g., a motor assembly, a haptic motor, direct-current (DC) motor, a brushless motor, etc.) in this example. In particular, the acoustic source <NUM> is implemented as an asymmetric motor in this example and communicatively coupled to the process control device <NUM>.

To facilitate acoustic coupling/attachment of the acoustic emission sensor <NUM> to the surface <NUM> by, a coupling agent or layer <NUM> such as, for example, a liquid, a gel, or any other suitable coupling agent may be used. In some examples, the use of a liquid or gel as the coupling layer <NUM> may improve the acoustic coupling by decreasing the amount of air gaps that would otherwise occur between the wear plate <NUM> and the surface <NUM>. In some other examples, the coupling agent or layer <NUM> may include a glue or partial glue-filler combination capable of providing stable acoustic coupling for long term use.

According to the illustrated example, to couple the motor <NUM> to the process control device <NUM>, a coupling agent or layer <NUM> (e.g., a liquid or gel) is used. In some examples, the type of coupling agent or layer <NUM>, <NUM> used to couple the acoustic emission sensor <NUM> and/or the motor to the surface <NUM> of the process control device <NUM> affects the quality of the acoustic path therebetween. Alternatively, the acoustic emission sensor <NUM> and/or the motor <NUM> may be coupled to the process control device <NUM> without a coupling agent or layer <NUM>, <NUM> using, for example, a mechanical fastener, a magnetic coupling, etc..

The acoustic test apparatus <NUM> also includes an example controller <NUM> and an operator workstation <NUM>. The operator workstation <NUM> may be operatively coupled to the controller <NUM> and/or the acoustic emission sensor <NUM>.

In operation, to control and/or vary an output signal to the motor <NUM>, the example controller <NUM> is operatively coupled to the motor <NUM> to provide an electrical signal (e.g., a voltage signal) to the motor <NUM>. Additionally or alternatively, data pertinent to the output signal (e.g., defined output functions) may be stored on a storage device of the controller <NUM> and/or the operator workstation <NUM> to facilitate remote access. In some examples, the electrical signal (e.g., input voltage signal sent to the motor <NUM>) may be varied to produce different corresponding acoustic signals (e.g., output acoustic signals from the motor <NUM>). For example, the acoustic signal may be varied in amplitude, frequency, pulse duration or duty cycle, etc. by the example controller <NUM>. In other words, characteristics of the acoustic signal waveform may be varied to suit the needs of a particular application.

To determine a functional and/or operating condition of the process control device <NUM> (e.g., to detect leaks in the process control device <NUM>) and/or monitor the structural health of the process control device <NUM>, the acoustic emission sensor <NUM> measures acoustic signals and transmits the measured acoustic signals using an analog communication interface. The piezoelectric element <NUM> may be operative to detect mechanical movement resulting in an acoustic signal. For example, the piezoelectric element <NUM> of the acoustic emission sensor <NUM>, which may be coupled to a valve or pipe, is operative to detect leaks in the valve or pipe. Additionally or alternatively, the acoustic emission sensor <NUM> can detect any other events and/or operational conditions corresponding to the process control device <NUM>.

According to the illustrated example, to test operation, a condition and/or functionality of the acoustic emission sensor <NUM>, an electrical signal (e.g., the voltage signal) is provided (e.g., transmitted) to the motor <NUM> to produce a specific acoustic output signal which, in turn, is measured by the acoustic emission sensor <NUM>. To identify and/or characterize the acoustic signals from the motor <NUM> that are measured at the acoustic emission sensor <NUM> so that an assessment of the operating condition of the acoustic emission sensor may be made, data associating the electrical signals to the acoustic signals output by the motor <NUM> are stored in a database. In some examples, the data is organized in a table, a chart, a graph, etc. The data may include acoustic reference signals corresponding to the electrical signals and/or the expected acoustic signals from the motor <NUM> so that conditional determinations of the acoustic emission sensor <NUM> may be made. Additionally, the data may be accessed remotely from an operator workstation such as, for example, the example operator work station <NUM>. In some examples, the acoustic emission sensor <NUM> may transmit the measured acoustic signal to the controller <NUM> and/or a second controller (e.g., a data acquisition system). The example controller <NUM> and/or the second controller may be operative to store and/or analyze the data (e.g., measured acoustic signals).

According to the present invention, the acoustic signal measured by the acoustic emission sensor <NUM> (e.g., the measured acoustic signal) is compared to data representing a reference/baseline acoustic signal. The data representing a reference acoustic signal may be stored in, for example, a table, a chart, or a graph that indicates the expected acoustic signal measured by the acoustic emission sensor <NUM> for each possible electrical signal sent to the motor <NUM>. In some examples, the reference acoustic signal is a previous signal (e.g., an initial signal, an original signal, a calibration signal, etc.) that was output by the motor <NUM> and measured by the acoustic emission sensor <NUM>. In some examples, the previous signal is used to track and/or characterize the acoustic emission sensor <NUM> and/or degradation of the acoustic emission sensor <NUM>. Alternatively, the reference acoustic signal may be equivalent to the acoustic signal output by the motor <NUM>. A deviation between the measured acoustic signal and the reference acoustic signal is determined based on a comparison between the measured acoustic signal and the data representing the reference acoustic signal. In some examples, the deviation is determined by comparing the values of the amplitudes of the reference signal and the measured acoustic signal. The deviation may be represented as a numerical value equivalent to the difference between the two amplitudes or as a percentage difference between the measured acoustic signal and the reference acoustic signal.

To characterize the acoustic signal from measured by the acoustic emission sensor <NUM>, a functionality or operational condition of the acoustic emission sensor <NUM> may be determined or assessed based on the deviation between the measured acoustic signal and the reference acoustic signal. The deviation between the measured acoustic signal and the reference acoustic signal may indicate an accuracy of measurements from the acoustic emission sensor <NUM> and/or the functionality of the acoustic emission sensor <NUM>. For example, if the deviation between the measured acoustic signal and the reference acoustic signal is greater than a threshold, the acoustic emission sensor <NUM> may need maintenance, repair or replacement. The acoustic emission sensor <NUM> may be designated as not functional if the difference between the measured acoustic signal and the reference acoustic signal is greater than a certain percentage (e.g., <NUM>%). An alert or alarm may be displayed via the operator workstation <NUM> indicating that the acoustic emission sensor <NUM> is malfunctioning. If the difference between the measured acoustic signal and the reference acoustic signal is less than the threshold, the acoustic emission sensor <NUM> may be considered to be functioning properly and not requiring repair or replacement. Additionally or alternatively, if a waveform and/or overall shape (e.g., a time-history shape) does not match a known expected waveform, the acoustic emission sensor <NUM> may be deemed to be malfunctioning. An appropriate message may be transmitted to the operator workstation <NUM> indicating the operational condition of the acoustic emission sensor <NUM>.

Electrical signals may be communicated to the motor <NUM> via any suitable wired or wireless connection. In some examples, the electrical signal (e.g., electrical input) is provided over the same connection connecting the acoustic emission sensor <NUM> to the database (e.g., to a data logging system). Alternatively, any other suitable means of communicating an electrical signal to the motor <NUM> may be implemented instead. In some examples, the controller <NUM> is also communicatively coupled to the process control device <NUM> via any suitable wired or wireless connection.

In some examples, the operator workstation <NUM> communicates with the controller <NUM>, the acoustic emission sensor <NUM>, and/or any other controllers or data acquisition systems via a wired or wireless communication protocol. For example, the operator workstation <NUM> may be remotely located (e.g., a location miles away) from the controller <NUM>, the acoustic emission sensor <NUM>, and/or any other controllers and may communicate via a wireless protocol to access data, trigger a check of the acoustic emissions sensor <NUM>, and/or perform diagnostic tests if any inconsistencies are detected within the system. The example acoustic emission sensor <NUM> may transmit measured acoustic signal data using an analog signal. Alternatively, any other suitable form of wired or wireless communication (e.g., analog or digital) may be used. In some examples, the electrical signal provided to the motor <NUM> may be determined and/or selected by an operator via the operator workstation <NUM> and/or the controller <NUM>. For example, the operator may determine a magnitude, frequency and/or timed pattern (e.g., a pulsed pattern) of the voltage of the electrical signal sent to the motor <NUM>. Additionally, the operator may determine a time at which to send the electrical signal to the motor <NUM>.

In some examples, the operator determines the times at which the electrical signal is sent to the motor <NUM> via the operator workstation <NUM> by defining a test schedule. Alternatively, the operator can manually send an electrical signal to the motor <NUM> (e.g., send an electrical signal on demand) via the operator workstation <NUM> and/or the controller <NUM> when the acoustic emission sensor <NUM> is to be tested. The operator may use the operator workstation <NUM> to create a test schedule to be followed by the controller <NUM>. In some examples, the test schedule indicates a specific time each day at which the controller <NUM> is to send an electrical signal to the motor <NUM>. In this manner, the electrical signal is transmitted to the motor <NUM> at the designated time(s) (e.g., the scheduled time(s)) without further input from the operator). In some examples, the schedule indicates that a test of the acoustic emission sensor <NUM> is performed on a weekly, monthly, or yearly basis. A test and/or measurement of an acoustic signal received by the acoustic emissions sensor may also be triggered by an event in the process control system such as, for example, a valve closing or opening. Transmitting the electrical signal to the motor <NUM> may include transmitting electrical pulses for a time period specified by an operator. Alternatively, the operator commands the controller <NUM> to continuously provide the motor <NUM> with an electrical signal. In such examples, the operator may designate a stop time or provide the motor <NUM> with an electrical signal (e.g., continuously) until the operator instructs the controller <NUM> to stop.

In some examples, the acoustic signal data measured by the acoustic emission sensor <NUM> is filtered to improve detection of the acoustic signal by the acoustic emission sensor <NUM>. In some examples, the testing of the acoustic emission sensor <NUM> is triggered by the controller <NUM> detecting an error and/or possible malfunction of the acoustic emission sensor <NUM>.

<FIG> is a detailed cross-sectional view of the example motor assembly <NUM>. As can be seen in the illustrated view of <FIG>, the motor <NUM> includes a mount (e.g., a coupling interface) or housing, which is implemented as an overmold (e.g., a potting material, a polymer, a silicone polymer, a neoprene mount, etc.) <NUM> that encases an electrical motor component (e.g., a DC motor, a haptic motor) <NUM>. According to the present invention, the electrical motor includes a haptic motor. In this example, electrical wires <NUM> penetrate the overmold <NUM> to electrically couple electric motor component <NUM> and/or the motor <NUM> to the example controller <NUM>. Alternatively, in some examples, the wires <NUM> are implemented as a single integrated wire that is electrically coupled to the motor component <NUM>.

In this example, a surface <NUM> of the overmold <NUM> is coupled to and/or affixed to the controller process control device <NUM> at the surface <NUM>. In particular, in some examples, the overmold <NUM> is pressed against the surface <NUM> to ensure suitable acoustic coupling between the electric motor <NUM> and the acoustic emissions sensor <NUM>. As mentioned above in connection with <FIG>, the surface <NUM> may be adhered to the surface <NUM>. In some examples, the overmold <NUM> may be elastically deformable so that the motor <NUM> and/or the overmold <NUM> can be coupled to and/or pressed against irregular, contoured and/or round surfaces to conform to these surfaces.

While the example overmold <NUM> is shown in a generally rectangular shape in this example, the overmold <NUM> may be any appropriate shape such as, but not limited to, round, cylindrical, circular, pentagonal, hexagonal, etc..

While the motor <NUM> of the illustrated example is implemented as an electric motor, an alternate acoustic source may be used including, but not limited to, a haptic device, a piezoelectric device, a speaker, a subwoofer, a tuning fork and/or a resonator. Further, any appropriate acoustic source that generates acoustic energy and/or waves may be used. Any of the described acoustic sources may be molded within and/or encased in a polymer material. According to the present invention, the acoustic source includes a haptic motor overmolded in a polymer.

<FIG> is a schematic overview of an acoustic signal analysis system <NUM> that may be implemented with the examples disclosed herein. In particular, the acoustic signal analysis system <NUM> is a computational system may be implemented in the controller <NUM> and/or the operator workstation <NUM> to verify or characterize a coupling of the acoustic emission sensor <NUM> and/or an operating condition of the acoustic emission sensor <NUM>. The acoustic signal analysis system <NUM> includes an analyzer <NUM>, which includes a sensor data analyzer <NUM>, a network control interface <NUM>, a signal data comparator <NUM>, an input command analyzer <NUM>, storage <NUM> with stored acoustic data <NUM> and an acoustic test signal controller <NUM>. In this example, the sensor data analyzer <NUM> is communicatively coupled to the acoustic emission sensor <NUM> via a communication line <NUM> and the acoustic test signal controller <NUM> is communicatively coupled to the motor <NUM> via a communication line <NUM>.

To verify an operational or functional status of the acoustic emission sensor <NUM>, the acoustic test signal controller <NUM> of the illustrated example directs the motor <NUM> to generate an output signal by providing a corresponding electrical signal/voltage to the motor <NUM>. As a result, the example acoustic emission sensor <NUM>, which is acoustically coupled to the motor <NUM>, measures and/or detects a corresponding signal (e.g., acoustic and/or vibrational signal) and, in turn, forwards the signal to the example sensor data analyzer <NUM>. According to the illustrated example, the sensor data analyzer <NUM> analyzes and/or converts/compiles the data so that the signal data comparator <NUM> can compare the measured data from the acoustic emission sensor <NUM> with the stored acoustic data <NUM>. In particular, the signal data comparator <NUM> may compared the measured data to a threshold and/or an expected waveform or signal pattern, which may be received and/or updated via the network control interface <NUM>, for example. In some examples, the sensor data analyzer <NUM> and/or the signal data comparator <NUM> causes the network control interface <NUM> to send a message to the controller <NUM> and/or the operator workstation <NUM> indicating that the acoustic emission sensor <NUM> is operating normally (e.g., within specifications) or malfunctioning.

In some examples, the input command analyzer <NUM> receives an input command from the operator workstation <NUM> to initiate testing of the acoustic emission sensor <NUM>. In some examples, the output signal generated by the motor <NUM> may be varied in amplitude, frequency and/or pulse duration(s) so that a measured signal at the acoustic emission sensor <NUM> can be compared to a characteristic expected measured signal that corresponds to the variances in the amplitude, the frequency and/or the pulse duration(s). In some examples, the motor <NUM> may transmit signals between <NUM> kilohertz (kHz) to <NUM> megahertz (MHz).

While an example manner of implementing the acoustic signal analysis system <NUM> of <FIG> is illustrated in <FIG>, one or more of the elements, processes and/or devices illustrated in <FIG> may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the example sensor data analyzer <NUM>, the example network control interface <NUM>, the example signal data comparator <NUM>, the example input command analyzer <NUM>, the example acoustic test signal controller <NUM> and/or, more generally, the example acoustic signal analysis system <NUM> of <FIG> may be implemented by hardware, software, firmware and/or any combination of hardware, software and/or firmware. Thus, for example, any of the example sensor data analyzer <NUM>, the example network control interface <NUM>, the example signal data comparator <NUM>, the example input command analyzer <NUM>, the example acoustic test signal controller <NUM> and/or, more generally, the example acoustic signal analysis system <NUM> could be implemented by one or more analog or digital circuit(s), logic circuits, programmable processor(s), application specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)) and/or field programmable logic device(s) (FPLD(s)). When reading any of the apparatus or system claims of this patent to cover a purely software and/or firmware implementation, at least one of the example sensor data analyzer <NUM>, the example network control interface <NUM>, the example signal data comparator <NUM>, the example input command analyzer <NUM>, and/or the example acoustic test signal controller <NUM> is/are hereby expressly defined to include a tangible computer readable storage device or storage disk such as a memory, a digital versatile disk (DVD), a compact disk (CD), a Blu-ray disk, etc. storing the software and/or firmware. Further still, the example acoustic signal analysis system <NUM> of <FIG> may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated in <FIG>, and/or may include more than one of any or all of the illustrated elements, processes and devices.

A flowchart representative of an example method <NUM> for implementing the acoustic signal analysis system <NUM> of <FIG> is shown in <FIG>. In this example, the method <NUM> may be implemented using machine readable instructions that comprise a program for execution by a processor such as the processor <NUM> shown in the example processor platform <NUM> discussed below in connection with <FIG>. The program may be embodied in software stored on a tangible computer readable storage medium such as a CD-ROM, a floppy disk, a hard drive, a digital versatile disk (DVD), a Blu-ray disk, or a memory associated with the processor <NUM>, but the entire program and/or parts thereof could alternatively be executed by a device other than the processor <NUM> and/or embodied in firmware or dedicated hardware. Further, although the example program is described with reference to the flowchart illustrated in <FIG>, many other methods of implementing the example acoustic signal analysis system <NUM> may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined.

As mentioned above, the example method <NUM> of <FIG> may be implemented using coded instructions (e.g., computer and/or machine readable instructions) stored on a tangible computer readable storage medium such as a hard disk drive, a flash memory, a read-only memory (ROM), a compact disk (CD), a digital versatile disk (DVD), a cache, a random-access memory (RAM) and/or any other storage device or storage disk in which information is stored for any duration (e.g., for extended time periods, permanently, for brief instances, for temporarily buffering, and/or for caching of the information). As used herein, the term tangible computer readable storage medium is expressly defined to include any type of computer readable storage device and/or storage disk and to exclude propagating signals and to exclude transmission media. As used herein, "tangible computer readable storage medium" and "tangible machine readable storage medium" are used interchangeably. Additionally or alternatively, the example method <NUM> of <FIG> may be implemented using coded instructions (e.g., computer and/or machine readable instructions) stored on a non-transitory computer and/or machine readable medium such as a hard disk drive, a flash memory, a read-only memory, a compact disk, a digital versatile disk, a cache, a random-access memory and/or any other storage device or storage disk in which information is stored for any duration (e.g., for extended time periods, permanently, for brief instances, for temporarily buffering, and/or for caching of the information). As used herein, the term non-transitory computer readable medium is expressly defined to include any type of computer readable storage device and/or storage disk and to exclude propagating signals and to exclude transmission media. As used herein, when the phrase "at least" is used as the transition term in a preamble of a claim, it is open-ended in the same manner as the term "comprising" is open ended.

The example method <NUM> of <FIG> begins as a coupling of the acoustic emission sensor <NUM> to the process control device <NUM> and/or an accompanying circuit or component corresponding to the acoustic emission sensor <NUM> is to be verified. In particular, the motor <NUM> generates a signal that is measured at the acoustic emission sensor <NUM> so that the measured signal can be compared to a threshold and/or an expected waveform to determine whether the acoustic emission sensor <NUM> is properly coupled and/or within operating specifications and, thus, operating normally.

According to the illustrated example, an acoustic signal is generated at the motor <NUM> (block <NUM>). In particular, the example acoustic test signal controller <NUM> directs the motor <NUM> to generate a signal to be detected at the acoustic emission sensor <NUM>.

Next, a corresponding acoustic output signal is detected at the acoustic emission sensor <NUM> (block <NUM>). In some examples, the sensor data analyzer <NUM> and/or the input command analyzer <NUM> directs the acoustic emission sensor <NUM> to enter a measurement mode (e.g., from a standby mode).

In this example, the signal data comparator <NUM> and/or the sensor data analyzer <NUM> compares the detected acoustic output to a reference signal or threshold to determine a condition of the acoustic emission sensor <NUM> and/or a deviation between the detected acoustic output and the reference signal (block <NUM>). In some examples, the signal data comparator <NUM> compares the detected acoustic output to a threshold (e.g. a numerical threshold). Additionally or alternatively, the signal data comparator <NUM> compares the detected acoustic output to an expected waveform/signal.

Next, it is determined whether the deviation is greater than the threshold (block <NUM>). In this example, if the sensor data analyzer <NUM> and/or the signal data comparator determines that this deviation is greater than the threshold (block <NUM>), control of the process proceeds to block <NUM>. Otherwise, the process proceeds to block <NUM>.

If the deviation is greater than the threshold, an error message indicating that the acoustic emission sensor <NUM>, associated structural integrity and/or a signal chain associated with the acoustic emission sensor <NUM> is not functioning properly is sent (block <NUM>). In particular, the network control interface <NUM> may be directed to send the error message to the controller <NUM> and/or the operator workstation <NUM>, for example.

If the deviation is not greater than the threshold, a message indicating that the acoustic emission sensor <NUM> and/or the signal chain associated with the acoustic emission sensor <NUM> is functioning properly is sent (block <NUM>). In this example, the network control interface <NUM> indicates to the controller <NUM> and/or the operator workstation <NUM> that the signal chain associated with the acoustic emission sensor <NUM> is properly operating.

Next, it is determined whether the test of the acoustic emission sensor <NUM> is to be repeated (block <NUM>). If the test is to be repeated (block <NUM>) control of the process returns to block <NUM>. Otherwise, the process ends. This determination may be based on whether further verification of the testing of the acoustic emission sensor <NUM> is required and/or when further testing is scheduled.

<FIG> is a block diagram of an example processor platform <NUM> capable of executing instructions to implement the method <NUM> of <FIG> and the acoustic signal analysis system <NUM> of <FIG>. The processor platform <NUM> can be, for example, a server, a personal computer, a mobile device (e.g., a cell phone, a smart phone, a tablet such as an iPad™), a personal digital assistant (PDA), a set top box, or any other type of computing device.

According to the illustrated example, the processor <NUM> also includes the example sensor data analyzer <NUM>, the example network control interface <NUM>, the example signal data comparator <NUM>, the example input command analyzer <NUM>, and the example acoustic test signal controller <NUM>.

The input device(s) <NUM> permit(s) a user to enter data and commands into the processor <NUM>.

The output devices <NUM> can be implemented, for example, by display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display, a cathode ray tube display (CRT), a touchscreen, a tactile output device, a printer and/or speakers). The interface circuit <NUM> of the illustrated example, thus, typically includes a graphics driver card, a graphics driver chip or a graphics driver processor.

Coded instructions <NUM> to implement the method <NUM> of <FIG> may be stored in the mass storage device <NUM>, in the volatile memory <NUM>, in the non-volatile memory <NUM>, and/or on a removable tangible computer readable storage medium such as a CD or DVD.

From the foregoing, it will be appreciated that the above disclosed methods, apparatus and articles of manufacture enable cost-effective and convenient (e.g., remote) evaluation of process control devices. The examples disclosed herein enable effective evaluation of acoustic emissions sensors by utilizing acoustic sources such as motors, asymmetric motors, haptic motors, speakers, piezoelectric devices, resonators and/or turning forks. According to the present invention, the acoustic source includes a haptic motor overmolded in a polymer.

Claim 1:
An acoustic test apparatus (<NUM>) for verifying operation of an acoustic emission sensor (<NUM>) coupled to a process control device (<NUM>), the acoustic test apparatus (<NUM>) comprising:
an acoustic source (<NUM>) adapted to be acoustically coupled to the process control device (<NUM>), the acoustic source (<NUM>) configured to generate an acoustic signal; and
a processor (<NUM>) configured to:
receive, from the acoustic emission sensor (<NUM>), a measured acoustic signal measured at the acoustic emission sensor (<NUM>) corresponding to the generated acoustic signal,
compare the measured generated acoustic signal to a baseline acoustic signal, and
determine an operational condition of the acoustic emission sensor (<NUM>) based on the measured acoustic signal and the comparison of the measured generated acoustic signal to the baseline acoustic signal;
the acoustic test apparatus being characterized in that the acoustic source (<NUM>) includes a haptic motor, wherein the haptic motor is overmolded in a polymer.