TH37796A - A complete measurement instrument for measuring fluid flow. - Google Patents

Abstract

DC60 (20/04/42) A flow switch or complete flow meter consisting of a measuring probe positioned into the flow path of the fluid. The aforementioned probe consists of two separate measuring electrodes, a power supply with a pair of terminals, one of which is connected to the measuring electrode, and the other of which is connected to the other measuring electrode. A resistive load is electrically inserted between one measuring electrode and the other of which is connected. A sensing device is connected to the other measuring electrode for sensing the potential drop between the measuring electrodes in the fluid. A comparator is electrically connected to the sensing device. The comparator is adjusted to compare the measured or sensing potential drop with a predetermined potential drop for a given flow. As it should be, the comparator consists of a second probe with two separate reference electrodes. The second probe is positioned in a relatively still area in the fluid, far from the measuring probe and reference electrodes. One reference electrode is electrically connected to the other measuring electrode, and a second resistive load is electrically inserted between the measuring electrodes. A sensing device is electrically connected to the other reference electrode. It is advisable that the resistive loads be of equal value and the polarity of the electrodes be uniformly reversed. A flow switch or complete flow meter consists of a measuring probe adjusted to extend into the flow path of the fluid. The aforementioned probe consists of two separate measuring electrodes. A power supply with a pair of terminals is connected. One of the aforementioned terminals is connected to one of the aforementioned measuring electrodes, and the other of the aforementioned terminals is connected to the other measuring electrode. A resistive load is electrically inserted between one of the aforementioned measuring electrodes and the other of the aforementioned terminals. A sensing device is connected to the other measuring electrode for sensing the potential drop between the aforementioned measuring electrodes along the fluid. A comparator is electrically connected to the sensing device. The comparator is adjusted to compare the measured or sensed potential drop with a predetermined potential drop for a given flow. As it should be, the comparison device consists of a second sounder with two separate reference electrodes. The second sounder is adjusted to protrude into a relatively still area in the fluid far from the measuring sounder. One reference electrode is electrically connected to the other measuring electrode, and a second resistive load is electrically inserted between the measuring electrodes. The sensing device is electrically connected to the other reference electrode. It is appropriate to ensure that the resistive loads are of equal value and that the polarity of the electrodes is uniformly reversed.

Claims (13)

1. A flow switch or flow meter consisting of: a probe adjusted to extend into the fluid flow path; the probe has two separate measuring electrodes; a power supply with a pair of terminals, one terminal connected to the aforementioned measuring electrodes, and the other terminal connected to the other measuring electrode; a resistive load electrically inserted between one measuring electrode and the other terminal; a sensing device connected to the other measuring electrode for sensing or measuring the potential drop between the measuring electrodes in the fluid; and a comparator electrically connected to the sensing device. This comparator is adjusted to compare the measured or sensed potential drop with the predetermined potential drop for the fluid at a predetermined flow. 2. A flow switch or complete flow measurement device conforming to claim 1, whereby the aforementioned comparative device consists of a second probe with two separate reference electrodes. The second probe is adjusted to extend into a relatively still area in the fluid at a distance from the probe. One reference electrode is electrically connected to the other terminal mentioned above. The first reference electrode is electrically connected to the other measuring electrode mentioned above, and one terminal mentioned above is electrically connected to the other measuring electrode mentioned above, and a second resistive load is electrically inserted between one terminal mentioned above and the other measuring electrode mentioned above. The sensing device mentioned above is electrically connected to the other reference electrode mentioned above. 3. Flow switch or flow measurement device, consisting of: a probe adjusted to extend into the fluid flow path, which has two separate measuring electrodes; a reference probe adjusted to extend into the fluid flow path farther from the probe; this reference probe has two separate reference electrodes; a power source for establishing the reference potential and a pair of terminals; the measuring electrode is electrically connected to one of the terminals and the reference electrode is connected to the other terminal; the first measuring electrode is electrically connected to one of the reference electrodes; a first resistive load is electrically inserted between one of the reference electrodes and the power source, and a second resistive load is electrically inserted between one of the measuring electrodes and the power source; a measuring device for measuring the potential between the resistive loads; and a comparator for comparing the measured potential to the reference potential. 4. The method for determining the flow or flow rate of a fluid involves placing a pair of separate measuring electrodes in the fluid channel where the flow or flow rate is to be determined. The aforementioned measuring electrodes are connected to their corresponding terminals on the power source, and a resistive load is connected between one electrode and its corresponding terminal on the power source. The potential drop between the aforementioned measuring electrodes in the fluid is measured. The potential drop is compared to the potential drop for a previously determined fluid when there is no flow, in order to provide a differential potential drop, and the flow and/or fluid volume from the aforementioned potential drop is determined. 5. The method that conforms to claim 4 consists of: the preparation of two separate electrodes, a second pair or a reference pair; the connection of one reference electrode to one terminal of the power supply; the connection of the other reference electrode mentioned above to the other measuring electrode mentioned above; and the connection of one terminal above to the other measuring electrode mentioned above; and the insertion of an electrical resistive load between one terminal above and the other measuring electrode mentioned above; the electrical connection of the sensing device to the reference electrodes mentioned above; the insertion of the reference probe into a significantly stationary area of the fluid; the detection of the measured potential with the sensing device mentioned above; and the comparison of the measured potential with the reference potential. 6. The method for determining the flow or flow rate of a fluid involves: inserting a probe in the fluid flow path where the flow or flow rate needs to be determined. This probe consists of two separate measuring electrodes. Inserting a reference probe in the fluid flow path, far from the probe. This reference probe consists of two separate reference electrodes. Providing a power supply that applies a reference potential. Connecting one terminal on the power supply to the first and second measuring electrodes, and the other terminal on the power supply to the first and second reference electrodes. Connecting one of the reference electrodes to one of the measuring electrodes. Arranging an electrically inserted resistive load between one of the reference electrodes and the power supply, and a second electrically inserted resistive load between one of the measuring electrodes and the power supply. Measuring the potential between the resistive loads and comparing the measured potential to the reference potential. 7. A method consistent with one of the claims in clauses 4 through 6 that involves uniform polarity reversal of the electrodes to achieve an appropriately long service life for the electrodes and/or to enable them to self-clean. 8. A method consistent with any of the claims in clauses 4 through 7 that involves shielding the reference probe from the fluid flow. 9. A method consistent with one of the claims in clauses 4 through 8 where the aforementioned relatively still region is provided by placing the aforementioned reference electrodes with a gap between them directly aligned with the direction of fluid flow, and the aforementioned measuring electrodes are placed with a gap between them that is at a significant right angle to the direction of fluid flow. 10. A second flow switch or flow measurement device conforming to one of the claims 1 through 3, whereby the measuring device comprises an active signal amplification circuit which measures, blocks, and amplifies a signal which is compared to a reference potential supplied by a power source. 11. A flow switch or flow measurement instrument that complies with any of the claims 1 through 3 or claim 10 and includes a calibration device where a predetermined reduction of the electrical potential between electrodes in the absence of flow can be achieved by setting it for water or any other sample of fluid being tested. 12. A flow switch or complete flow measurement device conforming to the claims, whereby the aforementioned device for calibration includes a device for adjusting the predetermined electrical potential reduction in the fluid when there is no flow. 13. A flow switch or complete flow measurement device conforming to claim 12, whereby the aforementioned device for calibration includes a device for adjusting the predetermined electrical potential reduction in the fluid when there is no flow.