Abstract: A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500° C. and about 800° C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

Abstract: A heater for use in heating a fluid flow through a passageway is provided that includes a continuous resistive heating element having a predefined shape that is directly exposed to the fluid flow. The predefined shape includes a cross-sectional geometry that provides a required heat distribution, structural strength, and reduced back pressure within the passageway. The predefined shape may include airfoils, while the cross-sectional geometry provides a required heat distribution, structural strength, and reduced back pressure within the passageway.

Abstract: A sensor for detecting material deposits in a fluid flow conduit includes a body and an array of pairs of temperature sensors disposed within the body, where each pair of temperature sensors is spaced a distance apart along a primary flow direction of the fluid flow conduit.

Abstract: A method of detecting accumulation of material deposits within a fluid flow conduit includes providing, by a controller, an excitation signal to a heating element of the fluid flow conduit. The method includes obtaining, by the controller, thermodynamic data of the fluid flow conduit in response to providing the excitation signal, where the thermodynamic data includes heat flux data, diffusivity data, time data, temperature differential data, or a combination thereof. The method includes determining, by the controller, an amount of material deposits based on the thermodynamic data.

Abstract: A method of adjusting a watt density distribution of a resistive heater includes designing a baseline heater circuit. A detection circuit is designed having a constant trace watt density and the detection circuit overlaps the baseline heater circuit. The detection circuit is manufactured, and its baseline thermal map is obtained. The baseline heater circuit is manufactured, and a nominal thermal map is obtained. A subsequent detection circuit is manufactured, and an actual thermal map is obtained. A subtraction thermal image is created by subtracting the baseline thermal map from the actual thermal map, and a subsequent baseline heater circuit is modified according to the subtraction thermal image.

Abstract: A method of calibrating temperature of a resistive element having a material with a Curie temperature includes generating a standard resistance-temperature (R-T) curve for the resistive element in isothermal conditions to identify values of the R-T curve and an inflection point at the Curie temperature, generating operational R-T curves for the resistive element over an operational time period, comparing the standard R-T curve to the operational R-T curves, and adjusting the operational curves to the standard R-T curve at the Curie temperature to calibrate temperature of the resistive element.

Abstract: A thermal system includes a base member, a two-phase fluid, a tuning heater, and a chuck. The base member includes at least one fluid passageway. The two-phase fluid is disposed within the fluid passageway. A pressure of the two-phase fluid is controlled such that the two-phase fluid provides at least one of heating and cooling to the base member. The tuning heater is secured to the base member. The chuck is secured to the tuning heater opposite to the base member. The tuning heater includes a plurality of zones to fine tune a heat distribution provided by the base member to the chuck.

Abstract: A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.

Abstract: A heater assembly includes a continuous series of perforated helical members and a plurality of heating elements. The perforated helical members cooperate to define a geometric helicoid disposed about a longitudinal axis of the heater assembly. Each perforated helical member defines opposed edges and a predetermined pattern of perforations. The perforations extend through each perforated helical member parallel to the longitudinal axis. The heating elements extend through the perforations.

Abstract: An electrostatic chuck is formed by depositing a diffuser layer onto an electrostatic puck and removing areas of the diffuser layer to form discrete diffuser segments separated by gaps. The discrete diffuser segments may define continuous concentric rings, discontinuous concentric rings, or a combination of continuous concentric rings and discontinuous concentric rings. The discrete diffuser segments are separated from each other by forming at least one trench in the diffuser layer. The trench may extend partially through the diffuser layer, completely through the diffuser layer to the electrostatic puck, or have a first portion that extends partially through the diffuser layer and a second portion that extends completely through the diffuser layer. Also, the trench can have a constant width or have a variable width.

Abstract: A method of predicting the temperature of a resistive heating element in a heating system is provided. The method includes obtaining resistance characteristics of resistive heating elements and compensating for variations in the resistance characteristics over a temperature regime. The resistance characteristics of the resistive heating element include, but are not limited to, inaccuracies in resistance measurements due to strain-induced resistance variations, variations in resistance due to the rate of cooling, shifts in power output due to exposure to temperature, resistance to temperature relationships, non-monotonic resistance to temperature relationships, system measurement errors, and combinations of resistance characteristics. The method includes interpreting and calibrating resistance characteristics based on a priori measurements and in situ measurements.

Abstract: A heater assembly includes a continuous series of perforated helical members and a plurality of electrical resistance heating elements. The perforated helical members cooperate to define a geometric helicoid disposed about a longitudinal axis of the heater assembly. Each perforated helical member defines opposed edges and a predetermined pattern of perforations. The perforations extend through each perforated helical member parallel to the longitudinal axis. The heating elements extend through the perforations.

Abstract: A method of monitoring a condition of a dynamic system includes installing a vibration signal acquisition device at a predetermined location of the dynamic system, acquiring vibration signals by the vibration signal acquisition device, analyzing the vibration signals in a frequency domain, and predicting a change in the condition of the dynamic system based on the vibration signals in the frequency domain. A system is also provided, and a condition of the dynamic system includes clogging.

Abstract: A heating system includes at least one electric heater disposed within the fluid flow system. A control device includes a microprocessor and is configured to determine a temperature of the at least one electric heater based on a model and at least one input from the fluid flow system. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.

Abstract: A method of adjusting a watt density distribution of a resistive heater includes designing a baseline heater circuit. A detection circuit is designed having a constant trace watt density and the detection circuit overlaps the baseline heater circuit. The detection circuit is manufactured, and its baseline thermal map is obtained. The baseline heater circuit is manufactured, and a nominal thermal map is obtained. A subsequent detection circuit is manufactured, and an actual thermal map is obtained. A subtraction thermal image is created by subtracting the baseline thermal map from the actual thermal map, and a subsequent baseline heater circuit is modified according to the subtraction thermal image.

Abstract: A control system for use in a fluid flow application includes a heater and a control device. The heater has at least one resistive heating element and the heater is operable to heat fluid. The control device determines at least one flow characteristic of a fluid flow based on a heat loss of the at least one resistive heating element and determines a mass flow rate of the fluid based on the at least one flow characteristic and a property of the at least one resistive heating element. And the property of the at least one resistive heating element includes a change in resistance of the at least one resistive heating element under a given heat flux density.

Abstract: A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500° C. and about 800° C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

Abstract: A heater is provided that includes at least one resistive heating element having a material with a non-monotonic resistivity vs. temperature profile and exhibiting a negative dR/dT characteristic over a predetermined operating temperature range along the profile. The heater can include a plurality of circuits disposed in a fluid path to heat fluid flow.

Abstract: A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.

Abstract: A heater system is provided that includes a base functional layer having at least one functional zone. A substrate is secured to the functional member, and a tuning layer is secured to the substrate opposite the base functional layer. The tuning layer includes a plurality of zones that is greater in number than the zones of the base functional layer, and the tuning layer provides lower power than the base functional layer. A component is secured to the tuning layer opposite the substrate, and the substrate defines a thermal conductivity to absorb and dissipate a requisite amount of power from the base functional layer. A control system is also provided that has a plurality of addressable control elements in electrical communication with power lines and with the tuning layer, the control elements providing selective control of the tuning layer zones.