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 circuit arrangement (1) for monitoring the temperature of an electronic component (2), which, in particular, can be impinged with an electric current and can be connected to at least one voltage source (3). The circuit arrangement is able to guarantee safe monitoring of the temperature of an electronic component impinged with electric current by the electronic component (2) being part of at least one Wheatstone bridge (7) and by at least one switching device (8) being provided that influences the impingement of the electronic component (2) with electric current on the basis of a bridge transverse voltage of the Wheatstone bridge (7). Additionally, circuit arrangement (1) is well suited for use in a calorimetric mass flowmeter (18).

A circuit arrangement (1) for monitoring the temperature of an electronic component (2), which, in particular, can be impinged with an electric current and can be connected to at least one voltage source (3). The circuit arrangement is able to guarantee safe monitoring of the temperature of an electronic component impinged with electric current by the electronic component (2) being part of at least one Wheatstone bridge (7) and by at least one switching device (8) being provided that influences the impingement of the electronic component (2) with electric current on the basis of a bridge transverse voltage of the Wheatstone bridge (7). Additionally, circuit arrangement (1) is well suited for use in a calorimetric mass flowmeter (18).

Degradation of reliability of a thermal fluid flow sensor, caused by generation of a crack in an insulating film is prevented in the thermal fluid flow sensor including a detection section and a circuit section formed on the same substrate when stress adjustment is performed by forming a deep concave portion in an interlayer insulating film in the detection section and forming the insulating film having a tensile stress thereon. As a means thereof, stair-like step is provided in a side wall of a concave portion, formed in the interlayer insulating film on a diaphragm. Accordingly, each depth of a first concave portion and a second concave portion, which form the concave portion, is reduced, and coatability of the insulating film for the stress adjustment, which covers a side wall and a bottom face of the concave portion, is improved.

A flow measurement probe includes an elongate probe having an averaging pitot tube with a plurality of upstream and downstream openings arranged along a length of the elongate probe, and a thermal flow measurement sensor coupled to the elongate probe. A method of measuring fluid flow rate in a process includes calculating a flow rate of the fluid using differential pressure in upstream and downstream openings of an averaging pitot tube in an elongate probe when the differential pressure is at least a defined measurement threshold, and calculating the flow rate of the fluid with a thermal mass flow sensor coupled to the flow measurement probe when the differential pressure is less than the defined measurement threshold.

A flow measurement probe includes an elongate probe having an averaging pitot tube with a plurality of upstream and downstream openings arranged along a length of the elongate probe, and a thermal flow measurement sensor coupled to the elongate probe. A method of measuring fluid flow rate in a process includes calculating a flow rate of the fluid using differential pressure in upstream and downstream openings of an averaging pitot tube in an elongate probe when the differential pressure is at least a defined measurement threshold, and calculating the flow rate of the fluid with a thermal mass flow sensor coupled to the flow measurement probe when the differential pressure is less than the defined measurement threshold.

System and methods for applying a liquid coating to a substrate are disclosed herein. One exemplary method includes a flow control routine in which the velocity of an applicator, or other parameter affecting the amount of material applied to the substrate, is iteratively adjusted. The amount of the adjustment performed in each iteration is tracked. When the sum of the adjustments by the flow control routine exceeds a predetermined threshold, a fan width control routine is initiated in which the fan width of the stream of material applied by the applicator is adjusted.

Traditional flow sensors include an upstream resistive sensor element, a downstream resistive sensor element and an intervening heater resistive element. To help reduce the size and/or cost of such flow sensor, it is contemplated that the heater resistor may be eliminated. When so provided, the space required for the heater resistive element, as well as the corresponding heater control circuit, may be eliminated. This can reduce the cost, size and complexity of the flow sensor. Coupling a resistive sensor element of such flow sensor to ground through a low temperature coefficient of resistance (TCR) resistor can reduce the variation of span of an output of the flow sensor which can improve resolution and accuracy of such sensor.

The present invention provides a thermal flow meter 300 which reduces a stress applied from a fixing portion 3721, which is used to hold and fix a circuit package 400 with respect to a housing 302, to the circuit package 400 and has high reliability. In the thermal flow meter of the invention, the circuit package 400 embedded with a flow rate measurement circuit is formed through a first resin molding process, the fixing portion 3721 is formed along with the housing 302 through a second resin molding process, and the circuit package 400 is enveloped by the fixing portion 3721, whereby the circuit package 400 is held by and fixed to the housing 302. In order to reduce the influence of a stress, generated based on a temperature change of the fixing portion 3721, on the circuit package 400, the fixing portion 3721 is constituted of a thick portion 4714 and a thin portion 4710. Since thickness of a resin of the thin portion 4710 is small, the stress to be generated is small, and a force applied to the circuit package 400 can be reduced.

The present invention provides a thermal flow meter 300 which reduces a stress applied from a fixing portion 3721, which is used to hold and fix a circuit package 400 with respect to a housing 302, to the circuit package 400 and has high reliability. In the thermal flow meter of the invention, the circuit package 400 embedded with a flow rate measurement circuit is formed through a first resin molding process, the fixing portion 3721 is formed along with the housing 302 through a second resin molding process, and the circuit package 400 is enveloped by the fixing portion 3721, whereby the circuit package 400 is held by and fixed to the housing 302. In order to reduce the influence of a stress, generated based on a temperature change of the fixing portion 3721, on the circuit package 400, the fixing portion 3721 is constituted of a thick portion 4714 and a thin portion 4710. Since thickness of a resin of the thin portion 4710 is small, the stress to be generated is small, and a force applied to the circuit package 400 can be reduced.