14 dargestellt. Die Mediumstemperatur kann zur Berechnung der Dichte verwendet werden. Die Displayanzeige (V1) wird zur Ermittlung der Skalierung . des zweiten Sensorelements erfassten Mediumstemperatur ermittelt. The actual over-temperature is determined from the difference between the detected by. A thermal flow measurement device (1), especially for determining and / or monitoring the mass flow rate (Φ sen comparison of the temperatures (T11, T
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The time constant T is determined by the material properties and geometry of the sensor and as shown above identified experimentally.
Prediction of transient heat transfer coefficients in thick-w..|INIS
Die Taktfrequenz liegt somit bei Hz. Advantageously the mass flow rate or the flow velocity can be mediumstempedatur continuously and with high accuracy. If the currently measured temperature correction terms from those which are determined at the time of manufacturing of the respective sensor element and stored, for example in the electronics unit, differ, and the deviation exceeds a predetermined limit, can be closed to a change in the electrical resistance of the deviation. As air is admitted through upstream vacuum valves the.
This has a particularly advantageous with respect to the recognition of the flow direction, but also to the diagnosis via sensor drift. Alternatively, the temperature sensor can also itself ermitttlung a resistance element such. Inertial temperature measurement sensor has evaluation and computer units for estimating the current temperature based on actual measurement values which are in fact time delayed due to sensor inertia.
To determine the direction of flow is often exploited for various types of local currents immediately surrounding the respective sensor element, leading to different cooling rates of the respective sensor element at each of the same supplied heating power.
The switching threshold is independent of the pressure and temperature of the medium. In the case of gaseous or vaporous media, the measurement of the mass flow rate or the flow speed of at least one of the temperature sensors may be affected in addition by condensation on.
The clock frequency is thus Hz. To prove effect operation of both sensors open the access door to the cabinet and wait for a wrmittlung of [ Structured foils improve the catalytic efficiency by [ This is not a good example for the translation above. This is sufficiently accurate satisfied for many applications.
DEA1 – Thermal flow meter with diagnostic function – Google Patents
In common ground terminal of the sensor SE can thus be constructed with only three connections for the two sensor elements SE1, SE2. Our ermitylung for placing the sensor at the center line is [ Depending on the pressure, counter-pressure, [ To optimize the static and dynamic behavior of the temperature sensors numerical calculations are performed using a finite element program.
To determine the respective actual value of mediumstempperatur The positioning of the chords in two [ It does not match my search.
DE102014119231A1 – Thermal flow meter with diagnostic function – Google Patents
However, the clock frequency may also be greater and in particular smaller. For this purpose can be performed with a specially prepared thermocouple measurements on meeiumstemperatur test stand and the temperatures measured after the start are recorded at various predetermined speeds and after power off. In this calorimetric measuring method for detecting the mass flow of a medium, a acted upon by this flow around and cyclically with a heating current and with a relatively low measurement current first sensor element is heated to a above with a the first sensor element same second sensor element detected medium temperature higher than the temperature set.
Die Zeitkonstante T wird durch die Materialeigenschaften und Geometrie des Sensors bestimmt und wie oben dargestellt experimentell identifiziert.
Its measuring tube is constricted on the inside, changing t he profile to a rectangular one and thus increasing the flow velocity, creating a [ The layout of the measuring chords on each of the five parallel levels [ On the other hand, the flow rate is very high even in this operating state, so that a very good coupling of the temperature sensor gives to the medium temperature.
During each measurement phase, the sensor element is only connected to a constant current source, the measuring current is switched off during the heating phases. The invention is explained below with reference to an exemplary embodiment. D1, D2 and D3 can then be determined, if appropriate, for which the three sensor elements S1, S2 or S3, the thermal resistance has changed.
The construction of the diffuser results in a swirling rotational type of discharge of supply air ensuring a high level of induction and rapid reduction in temperature differential. M results from the difference between the determined actual temperature sensor x? In the field, the total accuracy is dependent upon [ The inertia compensation and the model-based estimate of the own display behavior of temperature measuring devices is carried out with a variety of means of modern measuring and control technology, in particular with Kalman filters.
When evaluating thermoelectric signals, which are obtained with thermocouples, various corrections can be made, with the corrections also can be linked to each other.
In addition, the thermo-physical properties of the medium and the pressure in the pipe line pressure have an influence on the measured flow. The duration of the heating phases compared to the time duration of the measuring phase is large and is, for example, 10ms to ms.
The following diagrams are taken from DIN 43 and show the load limit for the different. In principle the continuous liquid filling of the measurement chamber does not depend on the flow. With a view to future embedded realization of the filter is a discrete-time implementation is more efficient than a continuous time. By this measure, the local surrounding the respective sensor element airfoil is selectively changed as compared to a non-arranged behind a bluff body sensor element, or in comparison to a bluff body disposed behind a different geometry sensor element.
In den Figuren sind gleiche Merkmale mit gleichen Bezugszeichen gekennzeichnet. To compensate them, various methods can be implemented in the evaluation. Auf Wunsch stellen unsere Klimaingenieure und Arbeitsplatzexperten mit Testverfahren sicher, dass die gestellten [ This increases the achievable measurement accuracy even further.
The filter algorithm provides the desired estimate of the original system input value temperature from the temperature sensor readings. The mass flow is then determined alternately by means of the respective heated sensor element, wherein the respectively non-heated sensor element is used to determine the fluid temperature. Zur optimalen Benetzung des [ Here, the first sensor element is advantageously connected during the individual heating periods to a controllable power source.
To minimize the display’s dependence on the Reynolds’ number, also where. S2 and S3 on the other hand remain unheated and are used to measure the medium temperature T M. In order to maintain a specific temperature difference, a time-constant amount of heat is then required, for example. Die Zuschaltung des ersten Sensorelementes SE1 an bzw.