A thermal sensor comprises an active element (41), e.g., a heater or cooler, at least one temperature sensor (31), and processing circuitry (50). The processing circuitry causes a change of power supplied to the active element (41). It then determines, at a plurality of times, a thermal parameter based on an output signal of the temperature sensors and analyzes the transient behavior of the thermal parameter. Based on this analysis, the processing circuitry determines a contamination signal that is indicative of a contamination on a sensing surface of the thermal sensor. If the thermal sensor comprises a plurality of temperature sensors arranged in different sectors of the sensing surface, a multi-sector thermal signal can be derived from the outputs of the sensors, and determination of the contamination signal can be based on the multi-sector thermal signal.

A thermal type flow meter includes a first resistor (R1) is disposed along a flow path through which a fluid flows, generating heat when a current is applied, and outputting a first output signal indicating a heat generation temperature, a second resistor (R2) disposed at a position different from that of the first resistor along the flow path and outputting a second output signal indicating a temperature of the fluid, and a current application unit configured to apply a current to the first resistor so that the first output signal indicates a predetermined temperature. A parameter for converting the difference between the first output signal and the second output signal when a predetermined input is received if the current is applied into a target value is determined. The flow rate is acquired using the parameter, the difference detected after the parameter is determined, and a predetermined function.

A thermal type flow meter includes a first resistor (R1) is disposed along a flow path through which a fluid flows, generating heat when a current is applied, and outputting a first output signal indicating a heat generation temperature, a second resistor (R2) disposed at a position different from that of the first resistor along the flow path and outputting a second output signal indicating a temperature of the fluid, and a current application unit configured to apply a current to the first resistor so that the first output signal indicates a predetermined temperature. A parameter for converting the difference between the first output signal and the second output signal when a predetermined input is received if the current is applied into a target value is determined. The flow rate is acquired using the parameter, the difference detected after the parameter is determined, and a predetermined function.

The design and structure of a fluidic concentration metering device with a full dynamic range utilizing micro-machined thermal time-of-flight sensing elements is exhibited in this disclosure. With an additional identical sensing chip but packaged at the different locations in the measurement fluidic chamber with a closed conduit, the device can simultaneously measure the fluidic concentration and the fluidic flowrate. With a temperature thermistor integrated on the same micro-machined thermal sensing chip, the disclosed device will be able to provide the key processing parameters for the fluidic applications.

The design and structure of a fluidic concentration metering device with a full dynamic range utilizing micro-machined thermal time-of-flight sensing elements is exhibited in this disclosure. With an additional identical sensing chip but packaged at the different locations in the measurement fluidic chamber with a closed conduit, the device can simultaneously measure the fluidic concentration and the fluidic flowrate. With a temperature thermistor integrated on the same micro-machined thermal sensing chip, the disclosed device will be able to provide the key processing parameters for the fluidic applications.

A thermal flow sensor device includes a storing portion that stores information about the relationship between a valve opening and a flow rate, an instruction portion that transmits an instruction signal specifying at least two predefined valve openings to a controlling device that controls the valve, an acquiring portion that acquires the flow rate output value of the thermal flow sensor, a calculating portion that calculates the magnification between two flow rate output values acquired by the acquiring portion, acquires the magnification between the two flow rates corresponding to the two valve openings acquired from the storing portion, and calculates the ratio of the magnification between the two flow rates to the magnification between the two flow rate output values as the correction coefficient, and a correcting portion that corrects the flow rate by multiplying the flow rate output value of the thermal flow sensor by the correction coefficient.

A thermal sensor device capable of maintaining measurement accuracy for a long period by suppressing plastic deformation due to thermal expansion of the heat generating resistor and reducing resistance change of the heat generating resistor, includes: a substrate having an opening; and a diaphragm having a structure in which a lower film, a heat generating resistor, and an upper film are stacked so as to bridge the opening, in which a film thickness of the lower film is larger than a film thickness of the upper film, an average thermal expansion coefficient of the lower film is larger than an average thermal expansion coefficient of the upper film, the lower film includes a plurality of films having different thermal expansion coefficients, and a film having a largest thermal expansion coefficient among the plurality of films is formed below a thickness center of the lower film.

A mass flowmeter employing thermal dispersion technology, and method for determining mass flow of a fluid throughout a range beyond that which possible for a constant T instrument at increasing power, and below that with which a constant power instrument can provide rapid T readings.

A mass flowmeter employing thermal dispersion technology, and method for determining mass flow of a fluid throughout a range beyond that which possible for a constant T instrument at increasing power, and below that with which a constant power instrument can provide rapid T readings.

Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector. The thermal flow meter includes a bypass passage through which a measurement target gas flowing through a main passage flows, and a circuit package which includes a measurement circuit for measuring a flow rate of the measurement target gas flowing through the bypass passage and a temperature detecting portion for detecting a temperature of the measurement target gas. The circuit package includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion molded by the resin. The temperature detecting portion is provided in the leading end portion of the protrusion, and at least the leading end portion of the protrusion protrudes to the outside from a housing.