In an embodiment, a method of sensing a flow comprises performing a measurement cycle for a first period of time, powering off the at least one upstream resistive element and the at least one downstream resistive element for a second period of time, and performing another measurement cycle for a third period of time. Performing the measurement cycle comprises supplying a current to the upstream resistive element and the downstream resistive element arranged in a bridge, resistively heating the upstream resistive element and the downstream resistive element to a temperature above an ambient temperature, and detecting an imbalance in the bridge resulting from a temperature difference between the at least one upstream resistive element and the at least one downstream resistive element in response to the flow of a fluid past the flow sensor.

Methods and apparatus for non-intrusively measuring fluid flow in a conduit, such as a pipe or tubing. The apparatus includes an insulator having self-adhesive inner surface attachable to the conduit, a temperature sensor on the inner surface of the insulator that senses the conduit surface temperature, a heat source on the inner surface of the insulator that imparts heat into the conduit, and a microcontroller connected to the heat source activator and the sensor assembly. In one embodiment, a baseline conduit temperature is measured, and the heat source raises the temperature of the conduit by a predetermined amount. When the conduit reaches target temperature, the heat source is deactivated and the cooling time for the conduit to return to its baseline temperature is measured. Fluid flow rate is determined from the cooling time, the temperature rise within a predetermined time, a temperature drop within a predetermined time, and/or a temperature gradient over time.

A method for determining a flow rate and/or a flow velocity of a medium interacting with at least a first and a second temperature sensor element and a heating element, wherein the method comprises the following method steps: heating the medium by means of the heating element for a predetermined heating duration, wherein the medium before the heating is largely in thermal equilibrium with at least the first and second temperature sensor elements; registering at least a first and a second measured value with the assistance of the first temperature sensor element and at least a third and a fourth measured value with the assistance of the second temperature sensor element for characterizing first and second temperature rises of the medium; and ascertaining the flow rate and/or flow velocity of the medium based on the at least two temperature rises.

A wind speed measuring device includes a constant temperature heat generating device that generates heat at a predetermined set temperature. The constant temperature heat generating device includes a power source, a heat generating element, a switching element, a comparator element, a first negative characteristic thermistor element, and a plurality of resistance elements. The heat generating element and the first negative characteristic thermistor element define a wind speed sensor. The switching element repeats turning on and off to make the heat generating element generate heat at a predetermined set temperature. A pulse voltage is applied from the power source to the heat generating element. A wind speed of a wind contacted with the wind speed sensor is calculated based on a wave form of the applied pulse voltage.

Provided is a vehicle-mounted system capable of transmitting a command to a first system from a second system during a period in which the first system communicates with the second system according to a unidirectional communication protocol. A vehicle-mounted system 100 includes a sensor 10 (first system) and an ECU (second system). The sensor 10 outputs a message signal including a pause pulse to the communication line DATA according to SENT (a unidirectional communication protocol). The ECU 20 is connected to the communication line DATA, and transmits a command to the sensor 10 using the falling period of the pause pulse.

Disclosed is an apparatus for determining a flow of a medium through a pipe, as well as a method for operating the apparatus. The apparatus comprises a heating element at least partially in thermal contact with the medium and which is heatable by means of a heating signal, and a first temperature sensor for registering a temperature of at least one component of the apparatus or the temperature of the medium. The heating element and the first temperature sensor are arranged outside of the pipe. The apparatus includes at least one coupling element, which is at least partially in thermal contact with the heating element, the first temperature sensor and/or a portion of the pipe or tube and serves to assure a thermal coupling between the heating element and the first temperature sensor and between the heating element and the medium.

A thermal flowmeter comprises a heating element thermally coupled to a flowing medium, a first temperature sensor and second temperature sensor. The first temperature sensor detects a flowing medium temperature in a region not affected by the heating element. The second temperature sensor detects a temperature of the heating element and also serves as a heating element. A control unit controls heating power of the heating element based on the difference between the detected temperatures at a predetermined time. The control unit provides a square wave signal to the second temperature sensor so that in a high phase it acts as heating element and in a low phase as a temperature sensor.

An apparatus includes a microfluidic channel and a flow sensor along the microfluidic channel. The flow sensor includes a heat emitting resistor for connection to an electric current source, analytical parameter sensor and electronics. The heat emitting resistor has a resistance that varies in response to temperature. The electrical parameter sensor is to sense an electrical parameter of the heat emitting resistor that is based on the resistance of the heat emitting resistor. The electronics determine a flow based on the sensed electrical parameter.

A differential thermal mass flow meter assembly (1) for measuring a mass flow of a gas or liquid is disclosed, wherein it comprises: a flow channel (2), in which the gas or liquid is flowing, at least two heating elements (4, 4, 4) arranged in the flow direction on the inside wall (3) of said flow channel (2), at least one thermal sensor (5) arranged in the flow direction up-stream said heating elements (4, 4, 4) on the inside wall (3) of said flow channel (2), at least one thermal sensor (6) arranged in the flow direction down-stream said heating elements (4, 4, 4) on the inside wall (3) of said flow channel (2), as well as a method of measuring the mass flow of a gas or liquid using said differential thermal mass flow meter assembly.

We disclose herein a CMOS-based sensing device comprising a substrate comprising an etched portion, a first region located on the substrate, wherein the first region comprises a membrane region formed over an area of the etched portion of the substrate, a flow sensor formed within the membrane region and a pressure sensor formed within the membrane region.