Abstract: A method and system for monitoring a heating arrangement includes applying a first polarity voltage to a heater of the heating arrangement, detecting a first polarity heating leakage current, applying a second polarity voltage to the heating arrangement, detecting a second polarity heating leakage current, and determining health of the heating arrangement via the first polarity heating leakage current and the second polarity heating leakage current.

Abstract: Apparatus and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element and leakage current, which is conducted from the resistive heating element to a conductive sheath surrounding the resistive heating element; ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element and/or the voltage across the resistive heating element.

Abstract: Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

Abstract: Apparatus and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element and leakage current, which is conducted from the resistive heating element to a conductive sheath surrounding the resistive heating element; ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element and/or the voltage across the resistive heating element.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by a power cable that includes a first power lead conducting an inlet current having an inlet current direction, and a second power lead conducting an outlet current having an outlet current direction opposite to the inlet current direction. The power cable passes through a center region of a toroid core one or more times, and a secondary winding on the toroid core is configured to induce a secondary voltage indicative of a difference between the inlet current and the outlet current, which defines the leakage current. The system includes a prognostic processor that is configured to calculate a heater health indication based on the secondary voltage, which is indicative of the heater health.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by first and second power leads which conduct an inlet and outlet current, respectively. The system includes an injection transformer with a number of primary turns that are inductively coupled to the first power lead, a signal generator configured to generate and supply a time-varying injection signal to the primary turns thereby imposing the time-varying injection signal on the inlet current, and a signal reader configured to receive a diagnostic signal from the heater, filter the diagnostic signal to pass a frequency associated with the time-varying injection signal, and produce a heater capacitance signal that is indicative of a capacitance value of the heater, where the heater capacitance signal is indicative of the health of the heater.

Abstract: Apparatus and associated methods relate to health-monitoring of a magnetic speed probe. An inductive coil of the magnetic speed probe is used for two purposes: i) to sense a changing magnetic field caused by rotation of a rotating member; and ii) to radiatively transmit radio-frequency signals for determining the health of the magnetic speed probe. A signal generator coupled to the inductive coil of the magnetic speed probe generates the radio-frequency signals that, when conducted by the inductive coil, causes an inductive coil to act as a radio transmitter by radiatively transmitting the radio-frequency signals. The radio-frequency signals transmitted by the inductive coil are detected by a radio receiver. The radio-frequency signals received are indicative of health of the magnetic speed probe.

Abstract: Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

Abstract: Apparatus and associated methods relate to determining health of an electrical heater of an air data probe based on a comparison between a calculated expected value and a measured value of an electrical property of the electrical heater. The expected value of the electrical property is calculated based in part on the electrical power provided to the electrical heater and further based in part on the aircraft flight parameters and/or environmental conditions. Such aircraft flight parameters and/or environmental conditions can include at least one of: electric power source status, airspeed, air pressure, altitude, air temperature, humidity, liquid water content, ice water content, droplet/particle size distribution, angle of attack, and angle of sideslip. These aircraft flight parameters and/or environmental conditions are received via an aircraft interface.

Abstract: Apparatus and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element and leakage current, which is conducted from the resistive heating element to a conductive sheath surrounding the resistive heating element; ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element and/or the voltage across the resistive heating element.

Abstract: Apparatus and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element and leakage current, which is conducted from the resistive heating element to a conductive sheath surrounding the resistive heating element; ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element and/or the voltage across the resistive heating element.

Abstract: Apparatus and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element and leakage current, which is conducted from the resistive heating element to a conductive sheath surrounding the resistive heating element; ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element and/or the voltage across the resistive heating element.

Abstract: Apparatus and associated methods relate to detecting leakage current in a powered electrical system. Leakage current is detected by comparing a high-frequency response signal with a high-frequency reference signal. A high-frequency excitation signal is coupled, via an inducer, into the powered electrical system at a first location. The high-frequency response signal is sensed, via a signal sensor, at a second location of the powered electrical system. Because the electrical dynamics of the powered electrical system can change in response to system degradation that results in leakage current, changes in the high-frequency response signal can be indicative of leakage. Thus, the high-frequency response signal is compared, by a controller, with a high-frequency reference signal. The high-frequency reference signal can be a high-frequency response signal obtained at a reference time, at which the powered electrical system is operating without leakage.

Abstract: Apparatus and associated methods relate to health-monitoring of a magnetic speed probe. An inductive coil of the magnetic speed probe is used for two purposes: i) to sense a changing magnetic field caused by rotation of a rotating member; and ii) to radiatively transmit radio-frequency signals for determining the health of the magnetic speed probe. A signal generator coupled to the inductive coil of the magnetic speed probe generates the radio-frequency signals that, when conducted by the inductive coil, causes an inductive coil to act as a radio transmitter by radiatively transmitting the radio-frequency signals. The radio-frequency signals transmitted by the inductive coil are detected by a radio receiver. The radio-frequency signals received are indicative of health of the magnetic speed probe.

Abstract: A system and method for monitoring leakage current in a heater connected to a heater power supply by a power cable having a first power lead conducting an inlet current defining an inlet current direction and a second power lead conducting an outlet current defining an outlet current direction that is opposite the inlet current direction. The system includes a differential current electromagnetic sensor having a magnetic core with a center region that the power cable passes through one or more times. The magnetic core has an air gap in which a magnetic flux sensing device is positioned and configured to provide a signal that is representative of magnetic flux across the air gap, which is indicative of a difference between the inlet current and the outlet current. This difference defines the leakage current.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by first and second power leads which conduct an inlet and outlet current, respectively. The system includes an injection transformer with a number of primary turns that are inductively coupled to the first power lead, a signal generator configured to generate and supply a time-varying injection signal to the primary turns thereby imposing the time-varying injection signal on the inlet current, and a signal reader configured to receive a diagnostic signal from the heater, filter the diagnostic signal to pass a frequency associated with the time-varying injection signal, and produce a heater capacitance signal that is indicative of a capacitance value of the heater, where the heater capacitance signal is indicative of the health of the heater.

Abstract: A system and method for monitoring leakage current in a heater connected to a heater power supply by a power cable having a first power lead conducting an inlet current defining an inlet current direction and a second power lead conducting an outlet current defining an outlet current direction that is opposite the inlet current direction. The system includes a differential current electromagnetic sensor having a magnetic core with a center region that the power cable passes through one or more times. The magnetic core has an air gap in which a magnetic flux sensing device is positioned and configured to provide a signal that is representative of magnetic flux across the air gap, which is indicative of a difference between the inlet current and the outlet current. This difference defines the leakage current.

Abstract: A system for an aircraft includes a heater comprising a resistive heating element and insulation surrounding the resistive heating element. A first current flows into the resistive heating element to provide heat and a second current flows out of the resistive heating element. The system further includes a leakage sensor configured to produce a leakage sensor signal representing a leakage current from the heater and a prediction processor configured to predict heater failure based on the leakage sensor signal.

Abstract: A system for an aircraft includes an aircraft component that includes a heater routed through the aircraft component, the heater including a resistive heating element and insulation surrounding the resistive heating element. A first current flows into the resistive heating element to provide heating for the aircraft component and a second current flows out of the resistive heating element. The system further includes a first sensor configured to produce a first sensor signal representing the first current, a second sensor configured to produce a second sensor signal representing the second current, a leakage sensor configured to produce a leakage sensor signal representing a leakage current, and a signal processor configured to sample and measure the first current, the second current, and a leakage current using a high frequency sampling rate to identify the presence of electric arcing. The detection of electric arcing is used to predict future heater failure and estimate heater remaining useful life.

Abstract: A method and system for monitoring a heating arrangement includes applying a first polarity voltage to a heater of the heating arrangement, detecting a first polarity heating leakage current, applying a second polarity voltage to the heating arrangement, detecting a second polarity heating leakage current, and determining health of the heating arrangement via the first polarity heating leakage current and the second polarity heating leakage current.