A METHOD INVOLVING MEASURING OF WATER QUALITY AND/OR DETECTION OF ONE OR MORE SUBSTANCES IN A WATER FLOW

Abstract

The present invention describes a method involving measuring of water quality and/or detection of one or more substances in a water flow, said method involving the steps of using a sensor system comprising at least two electrodes, for sending frequency from at least one electrode and receiving a response from at least another electrode, wherein the method involves filtration over one or more frequency ranges in the response, to measure the impedance and using the impedance as an indicator of the water quality and/or for detection of one or more substances in the water flow.

Claims

1. A method involving measuring of water quality and/or detection of one or more substances in a water flow, said method involving the steps of using a sensor system comprising at least two electrodes, for sending frequency from at least one electrode and receiving a response from at least another electrode, wherein the method involves filtration over one or more frequency ranges in the response, to measure the impedance and using the impedance as an indicator of the water quality and/or for detection of one or more substances in the water flow.

2. The method according to claim 1, wherein said at least two electrodes are positioned at a distance opposite or substantially opposite each other and a first electrode sends a frequency and a second electrode receives a response.

3. The method according to claim 1, wherein sending a frequency involves sending a sinusoidal frequency signal.

4. The method according to claim 1 wherein the method involves sending multiple sinusoidal signals in different frequencies and wherein the method involves matching multiple filtrations in the response.

5. The method according to claim 1, wherein the method involves sending at least one frequency sweep between two frequencies and receiving a response over said at least one frequency sweep.

6. The method according to claim 1, wherein the method involves sending a frequency noise between two frequencies and receiving a response over said at least one frequency noise.

7. The method according to claim 5, wherein the filtration is performed over one or more filtration ranges in the response.

8. The method according to claim 1, wherein the filtration involves applying a FT (Fourier Transform), FIR (Finite Impulse Response), IIR (Infinite Impulse Response), or a combination thereof.

9. The method according to claim 1, wherein frequencies used are in the range of from 0-100 kHz.

10. The method according to claim 1, wherein the method involves sending different frequencies and receiving responses for each frequency used.

11. The method according to claim 1, wherein more than two electrodes are used and wherein at least two electrodes send frequencies at different levels.

12. The method according to claim 1, wherein the method involves at least two individual method steps which include sending frequencies, preferably as one or more sinusoidal signals, frequency noises or frequency sweeps or a combination thereof, and receiving multiple responses.

13. The method according to claim 1, wherein an envelope detector transforms a received and filtrated signal to a new signal based on the amplitude of the received and filtrated signal.

14. The method according to claim 13, wherein the signal from the envelope detector is used to identify one or more amplitude peaks and/or changes in the amplitude of the received and filtrated signal.

15. The method according to claim 1, wherein the method is performed in a water recirculation system intended for recycling of water or discarding of water not suitable to recycle, said water recirculation system comprising a flow path for recirculation, at least one water treating unit, and a sensor unit arranged for measurement of at least water quality, and wherein the sensor unit is connected to the control unit which decides if water should be recycled or discarded in a point of separation based on the measurement of water quality, said water recirculation system also comprising a heating source and a user outflow arranged at the end of the flow path for recirculation.

Description

DESCRIPTION OF THE DRAWINGS

[0023] In FIG. 1A there is shown a graph representing a first generic alternative according to one embodiment of the present invention. On the y axis the voltage (V) is shown, and one the x axis the frequency (F) is shown. It should be noted that the voltage is a direct measure of the impedance according to standard equations in laws of science of electricity and physics.

[0024] As you will see, in this case the method involves sending on frequency (“signal”) from one electrode which is then received by another electrode. In the method, a filter is used. This filter filtrates over only a small range of the frequencies, where the signal is within this range. Moreover, the noise is also depicted in the graph. As is evident, the relationship of signal to noise will be better when using the method according to the present invention.

[0025] As an example, the actual signal may be in the form of sinusoidal frequency signal, as is described above.

[0026] In FIG. 1B there is shown another embodiment according to the present invention. This embodiment is corresponding to the one shown in FIG. 1A, however in this case there are two different signals/frequencies sent and received and also two corresponding filters used.

[0027] In FIG. 1C there is shown another embodiment of the method according to the present invention. In this case, the graph is intended to show a method wherein a frequency sweep is used. As notable, then different signals are sent in a specific frequency range. Moreover, for all new signals sent, then a corresponding filter with a frequency range corresponding to the sent signal is used for filtration.

[0028] As may be understood from above, when using several signals and filters, the method according to the present invention may be improved. This alternative according to the present invention implies that more valuable data may be obtained during a reasonable time. If the method instead would involve using the entire frequency band range, then such a sweep and the data handling thereafter would take a comparatively long time. For instance, when operating a water recirculation system based on water quality measurements by use of a method according to the present invention, then it is of interest to ensure a short response time. By using several frequency ranges or frequencies of great data interest and excluding others of no data interest, then the response time may be shortened. Again, the method according to the present invention still provides very valuable data in certain set frequency ranges suitable when deciding water quality in a water flow, and does so in a very fast response time.

[0029] In FIG. 2 there is shown a possible set-up according to one embodiment according to the present invention. A signal generator enables a signal to be generated in one electrode. Another electrode, arranged opposite the electrode providing the signal, receives the signal. As seen, a filter is used to ensure to filtrate a frequency range suitable to match the signal sent. Moreover, an envelope detector is used to transform the received and filtrated signal to a new type of signal which is based on the amplitude in the received and filtrated signal. Therefore, according to one specific embodiment of the present invention, an envelope detector transforms a received and filtrated signal to a new signal based on the amplitude of the received and filtrated signal. Furthermore, according to yet another specific embodiment of the present invention, the signal from the envelope detector is used to identify one or more amplitude peaks and/or changes in the amplitude of the received and filtrated signal. To obtain such data based on the amplitude may be valuable when measuring water quality, e.g. in a water flow in water recirculation system such as further mentioned below.

[0030] In FIG. 3 there is shown a water recirculation system in which the method according to the present invention suitably may be used. According to one embodiment, the water recirculation system 1, intended for recycling of water or discarding of water not suitable to recycle, comprises a flow path for recirculation 50, at least one water treating unit 6, and a sensor unit 7 arranged for measurement of at least water quality, where the sensor unit 7 is connected to the control unit which decides if water should be recycled or discarded in a point of separation 30 based on the measurement of water quality, said water recirculation system 1 also comprising a heating source 100 and a user outflow UO arranged at the end of the flow path for recirculation 50. As may be noted, in this case the water recirculation system is in the form of a shower, however also other applications are possible, e.g. sinks or integrated systems with several such components.