A method of forming a substrate support in a substrate processing system includes forming at least one ceramic layer and arranging a plurality of thermal elements adjacent to the ceramic layer in one or more thermal zones. Each of the thermal zones includes at least one of the thermal elements and each of the thermal elements includes a first resistive material having a positive thermal coefficient of resistance (TCR) and a second resistive material having a negative TCR. The second resistive material is electrically connected to the first resistive material. At least one of the first resistive material and the second resistive material of each of the thermal elements is electrically connected to a power supply to receive power and each of the thermal elements heats a respective one of the thermal zones based on the received power.

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.

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.

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.

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.

The present invention relates to a method and device for measuring the temperature in power resistors based on the measurement of the high-frequency circuit parameters of said resistor. The present invention excludes the use of thermocouples, dedicated temperature sensors or thermo chambers.

A control system for use in a fluid flow application is provided. The control system includes a heater having at least one resistive heating element. The heater is adapted to heat the fluid flow. The control system further includes a control device that uses heat loss from at least one resistive heating element to determine flow characteristics of the fluid flow.

A substrate support for supporting a substrate in a substrate processing system includes a plurality of thermal elements. The thermal elements are arranged in one or more thermal zones, and each of the thermal zones includes at least one of the thermal elements. Each of the thermal elements includes a first resistive material having a positive thermal coefficient of resistance and a second resistive material having a negative thermal coefficient of resistance. The second resistive material is electrically connected to the first resistive material. At least one of the first resistive material and the second resistive material of each of the thermal elements is electrically connected to a power supply to receive power, and each of the thermal elements heats a respective one of the thermal zones based on the received power. At least one ceramic layer is arranged adjacent to the thermal elements.

An operating method for an electric heater having at least one control unit with at least one temperature sensor measuring a reference temperature, and at least one heating element having a positive temperature coefficient mode above a critical temperature and a negative temperature coefficient mode below the critical temperature, may include heating a fluid passing the electric heater to an outlet temperature by the at least one heating element, and operating the electric heater in one of a normal mode or a protection mode. In the normal mode, the at least one heating element may be supplied with at least one of a direct current and a direct voltage. In the protection mode, electrical power supplied to the at least one heating element may be regulated by pulse width modulation. The electric heater may be operated in the normal mode if the reference temperature is less than or equal to the critical temperature, and in the protection mode if the reference temperature is greater than the critical temperature.

Disclosed is a multilayer structure, comprising: a first heater layer comprising a CNT heater, wherein the CNT heater comprises a composite of carbon nanotubes and silicone; and a second heater layer comprising a PTC heater, wherein the PTC heater comprises a composite of carbon black and polymer; wherein the first heater layer and the second heater layer are first and second respectively in an electrical series; wherein the first heater layer has a negative temperature coefficient with respect to electrical resistivity; and wherein the second heater layer has a positive temperature coefficient with respect to electrical resistivity. Also disclosed is an aircraft component comprising the multilayer structure.