Abstract:
An affordable, low-power, low-profile water contamination detection and/or filtration device that can be installed directly onto a home faucet or other water line. The contamination detection part uses photometric and other sensors to collect data pertaining to levels of Total Organic Carbon, Total Dissolved Solids, heavy metals, turbidity, harmful bacteria, and other contaminants. The device uses efficient circuit design so that parts of the sensor, LED, and calculation circuit are only activated when the faucet is turned on and water fills a measurement chamber. The filtration part of the device can be switched on and off using simple twist interface, such that filtered water can flow directly into the contamination detection part for testing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application is a continuation-in-part of U.S. patent application Ser. No. 15/174,809, filed on Jun. 6, 2016, which claims the benefit of priority to U.S. Patent Appl. No. 62/172,119, filed on Jun. 7, 2015. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to the field of water contaminant detectors and filters. 
       BACKGROUND OF THE INVENTION 
       [0003]    Water safety and purity is a civic necessity of utmost importance. Human health and safety dictates that drinking and other home use water must meet various health and environmental standards. Contaminated equipment or fluids at various sources in the water supply can affect thousands of homes and lives. Sabotage and attacks on the water supply must not only be prevented, but rapidly detected. Consumers feel increasingly insecure about the water in their home taps. Despite water purification by state and local municipalities, many consumers install filtration systems in order to purify their water. 
         [0004]    Public water utilities and state and local agencies typically perform contaminant detection at water treatment centers, public water supplies and wells, and other central locations in the water distribution system by grab sampling, which means that technicians collect field samples or perform measurements in the field. A common analytic technique for measuring water quality is to determine the level of Total Organic Carbon (“TOC”) in the water. TOC can come from decaying organic matter or synthetic sources such as industrial chemicals or fertilizers, and as such is an indicator of water quality. 
         [0005]    Typical TOC analyzers are large and expensive devices that are best suited for utilization on-site at central locations in the water supply. Some devices burn the sample in a furnace then analyze remaining CO 2 , which is directly proportional to the amount of carbon in the sample. More recently, UV254 has been used as a TOC substitute, wherein the amount of UV254 absorbed by the water is known to be proportional to the concentration of organic carbon matter in the water. Devices that use UV254 typically use a large light source with large power requirement, for high accuracy measurement. Furthermore, these instruments use a standing sample of water, to further increase their accuracy. 
         [0006]    Other water contaminants that consumers seek to detect and filter include heavy metals, Total Dissolved Solids (TDS), turbidity, and other bacteria. Many types of filters are commercially available to trap and remove pollutants such as organic and man-made chemicals, heavy metals, sediments, radioactive isotopes, etc. Such filters come in many forms, including activated carbon, carbon block, reverse osmosis, and ion exchange filters. Typical commercially available consumer filters are contained within water pitchers, installable onto faucets and taps, and some are incorporated into the building&#39;s plumbing. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention is the first affordable, low-power, low-profile device that can be installed directly onto a home faucet or other water line, enabling contamination detection in real-time. Instead of relying exclusively on municipal testing for ascertaining water contamination, residents can now test for TOC and other contaminants directly from their own tap. Instead of purchasing water filtration systems and/or bottled water, consumers can now rely upon a device installed on their own tap for integrated detection and filtration. In addition, the device incorporates a replaceable filter that can be switched on and off as needed, so that the user can filter water for drinking or let water flow unfiltered for other uses. 
         [0008]    The device comprises a measurement part that identifies contaminants in a flow of water from the tap. Water is diverted from the flow of the tap into a sampling chamber where turbulence is minimized. When the sampling chamber is sufficiently full of water, one or more electronic receivers disposed in or around the sample chamber is automatically activated to collect data regarding the water in the chamber. This data is processed by an efficient integrated circuit and then transmitted for display, either externally on the surface of the device, or wirelessly to a user&#39;s mobile device. 
         [0009]    Minimal turbulence in the sampling chamber, automatic activation, highly efficient integrated circuit, and optional redundant data collection all contribute to the accuracy of the contaminant calculation, and to the ability to build the device to low power specifications. The result is a small and efficient device that is simple to package, ship, handle, install and use with consumer taps. 
         [0010]    An application can be installed to a user&#39;s personal mobile device with an application for displaying a variety of contamination information to the user. This information can include, but is not limited to, the level of each type of contaminant detected in the water, comparisons to recommended safety levels, water filter replacement recommendations, and locations of water contamination events as detected by similar devices installed by other consumers. It can also convey information about the device itself, such as the status of the water filter and whether the filter needs to be replaced. The application may send and receive data from a server for storage and retrieval of water contamination data. A central repository of water contamination data from the described devices may help governments and municipalities identify and solve problems in the water supply. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a depiction of an embodiment of the device in an environment of use. 
           [0012]      FIG. 2  is a side view, in partial perspective, some parts being depicted with transparency. 
           [0013]      FIG. 3  is a side view of the inside of an embodiment of the device. 
           [0014]      FIG. 4  is a top view, in partial perspective, of the inside of an embodiment of the device. 
           [0015]      FIG. 5  is a side of an embodiment of the measurement chamber of the device. 
           [0016]      FIG. 6  is an exemplary measurement circuit for the device. 
           [0017]      FIG. 7  is a system schematic of the device operable to send data to a remote apparatus such as a phone. 
           [0018]      FIG. 8  is a sample remote apparatus displaying data received from the device. 
           [0019]      FIG. 9  is a side perspective view of the inside of an embodiment of the device. 
           [0020]      FIG. 10  is a top view, in partial perspective, of an embodiment of the device. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    As noted in the Background, typical water contaminant detectors are large devices that are applied to standing water. Consumers have no means to monitor contaminants in their own residences or commercial spaces. An installable device  1  is described that can be installed directly onto a tap  2 . An example of the device in the consumer tap environment is shown in  FIG. 1 . The device comprises a measurement unit  3  and can optionally also comprise a filter unit  40 . The measurement unit contains functionality to detect and monitor contaminants inside the water, while the filter unit functions to filter contaminants out. 
         [0022]    The filter unit comprises a compartment  43  holding replaceable filter  49  that can be utilized when activated by rotating the filter unit using external switch  42 . Using the device installed directly onto their tap, the user can filter water, test the filtered water for impurities, and test unfiltered water for impurities, all seamlessly from the tap. 
       Measurement Unit 
       [0023]    When the tap  2  is operated, water flows through the device and into entrance  4 . As shown in  FIG. 4 , most of the water will flow through the measurement unit entrance  4 , but a portion of the flow will enter diversion opening  24 , which diverts water flow through a conduit  5  into a measurement chamber  6 . The device comprises one or more electronic receivers, e.g.  11  and  12 , for receiving information about the fluid within the chamber  6 . 
         [0024]    Efficiency and accuracy of the one or more electronic receivers is facilitated by reducing the turbulence of fluid within the chamber  6 . In the preferred embodiment, as demonstrated in  FIG. 4 , water flows into chamber  6  from the base of said chamber to fill. Whereas a downward waterfall of fluid would cause air bubbles and turbulence, water flow from the base of the chamber causes air bubbles and turbulence to be minimized. Reduction of turbulence, air and other causes of refraction results in more efficient and accurate measurement of light by photometric sensors. Yet the water need not flow into the base of the chamber to achieve this result. For instance, water flow from the top of the chamber may be slowed by a buffer. As another example, the chamber may be shaped to facilitate the dissipation of air bubbles, such as by having a large horizontal cross-section at the top. And while the device illustrated here is installed into a tap water faucet, it is contemplated that the device could be installed in different parts of the water line wherein it may comprise a different conduit for diversion of water flow. Furthermore, the conduit  5  depicted in  FIGS. 3 and 4  is tubular in order to illustrate the diversion of flow more clearly, but may obviously take on any shape or form. Finally, as would obviously be necessary to return water to the flow out of the tap for drinking or use, the chamber can also comprise one or more exits  25  and/or  26 . 
         [0025]    The system also comprises one or more LEDs, such as  9  and  10 , situated in or near chamber  6  to emit light into the chamber. At least one of the receivers is a photometric sensor that measures light absorption of the fluid when the chamber is substantially full. As noted above, reduction in turbulence and air in the water greatly facilitates the operation of photometric sensors that receive light passing through the water. LEDs are known to have low power requirements, further minimizing the size and energy needed by the device. The sample chamber  6  is preferably a quartz cuvette, or similarly comprised of a material known for high conductivity of UV254, to increase the accuracy of photometric measurements from the chamber. The LEDs and receivers can be located anywhere around chamber  6 , not necessarily on opposite sides. For instance, LED  9  is located at a right angle to receiver  12  in the embodiment depicted in  FIG. 2 . In order to further increase the accuracy of the light absorption measurements of the one or more receivers the LED can be enclosed within a solid casing  90  with small opening  91  near the chamber, so that light is directed through the chamber and prevented from reflection or diffusion by the external surface of the chamber. 
         [0026]    The preferred embodiment uses ultraviolet light absorption, preferably at a wavelength of 254 nm (UV254), to correlate with and therefore measure Total Organic Carbon (TOC) contaminants in the water. Ultraviolet wavelengths in the range of 250 to 300 nm are known to be closely correlated to TOC levels, UV254 having a high adjusted coefficient of determination of 0.997. 
         [0027]    A photometric sensor can also be used to measure infrared (IR), which is an indicator of turbidity. IR correlates to turbidity, which is a type of contaminant data, but the IR absorption can also be used to refine TOC calculation. Furthermore, a temperature probe situated in or near the cuvette may further refine the calculation to account for changes in light strength due to temperature fluctuations. TOC can be determined according to the following formula: 
         [0000]      TOC= K   toc   *K   D2*   *D 2*1 g ( A 0*(1− Ka*T )/ D 1)
 
         [0028]    Where K toc  is the TOC coefficient, K D2*  is the IR turbidity coefficient, D 2  is the turbidity ADC measurement, A0 is UV intensity at 0° C., Ka is the UV/temperature intensity coefficient, T is temperature, and D 1  is the UV TOC ADC measurement. The TOC coefficient may be adjusted to account for the ultraviolet wavelength actually used. 
         [0029]    A sample schematic of a measurement circuit for the calculation of TOC is shown in  FIG. 6 . The circuits can be located on one or more PCBs, such as  8  and  9 . Photodiode receiver  12  capable of receiving UV254 and/or IR transmits current proportional to light absorbed to preamplifier circuit  30 . Filter &amp; average and/or additional signal processing may be performed by circuit  31 . Furthermore, temperature sensor  35  may transmit temperature near the photodiode to temperature processing circuit  36 . UV, IR and temperature data is used to perform the TOC calculation by algorithm module  33 . 
         [0030]    In order to conserve power, the LEDs are activated only when the chamber  6  is substantially full.  FIG. 5  demonstrates two different ways to implement this functionality. In a first example, conductive metal plates  13  and  14  are situated on each side of the top of chamber  6 , such that together they form a capacitor. Fluid filling the chamber  6  causes voltage change, which causes the LED circuit to be activated. In a second example, by positioning an LED at an angle—such as the 45 degree angle of LED  9  depicted by example in  FIG. 5 —light from the LED is not received by a receiver until the water level in chamber  6  exceeds that of the light source  9 , due to refraction. Thus, the detection of light from LED  9  may be used to activate the UV254 LED and/or measurement circuit. 
         [0031]    As described here, the preferred embodiment requires a mere 500 μA of power consumption when the circuit is not activated. Upon activation of UV254 and the TOC measurement circuit, power consumption rises to around 15 mA, but only for the time needed to complete the calculation. Thus, the use of LEDs, automatic activation, high quantum efficiency photodiodes, and accurate signal processing each contribute to the low power consumption of the device. 
         [0032]    Power may be delivered by any means, including by battery pack  20  as depicted, or any other means including, but not limited to, AC/DC, solar and hydroelectric power. The low power requirement of the device enables the use of low power sources such as solar. Solar panels may be located directly on the outer casing of the device. The battery pack may be removable, replaceable, and/or rechargeable by USB or a wall outlet connection. 
         [0033]    Other embodiments may comprise any combination and types of receivers. The positioning of receivers depicted in the drawings is exemplary, and receivers may be located anywhere on, near or inside of the chamber. Receivers may be any type of receivers currently known in the art, including, but not limited to, photometric sensors for receiving light, temperature probes for determining temperature, and electrodes for measuring resistance. For instance, Total Dissolved Solids (TDS) correlate with conductivity and may be measured by determining the resistance between two electrodes within the sample chamber. TDS, or Total Dissolved Solids, is a measure of the combined inorganic and organic substances in the water, and as such is another useful measure of contamination. As another example, voltage between an electrode within water in the sample chamber, and another electrode within a fixed pH liquid, may be used to determine pH of the water. 
         [0034]    The device may comprise a low-power Bluetooth module  32  to transmit contamination information to a remote apparatus operable to receive data from the device.  FIG. 7  is a schematic showing the device  1  in Bluetooth or other wireless connection to smartphone  50 . Smartphone device  50  may also be capable of sending and receiving data to server  60  for the collection and management of user water contamination data. The display of contamination information need not be remote, however, indeed may be anywhere on the device itself, such as on its external casing. For instance, a screen or LED signal can be incorporated onto the outside of the device. 
         [0035]    The remote apparatus  50  can receive and process contamination data according to methods already known in the art. The remote apparatus can be programmed to receive and display data as the programmer desires. For instance,  FIG. 8  shows a display screen  51  on user device  50 , the display screen showing current levels of heavy metals, turbidity, bacteria, TOC, TDS and PH that has been transmitted from device  3 . 
       Filter Unit 
       [0036]    The device can further comprise optional filter unit  40 . The filter unit comprises a compartment  43  holding a replaceable filter  49 . Filter functionality can be turned “on and off” such that the user can have filtered water only when needed, conserving the lifetime of the filter. The on/off functionality is incorporated into the design of the device, intuitively operated by rotating the filter unit around the axis of tap  2 . When housing  41  is rotated, an internal switch  46  coupled to the filter unit housing  41  reveals an opening  47  leading to filter compartment  43 . Filter compartment  43  holds a replaceable filter  49 . The filter  49  can be a cylindrical carbon filter that fits into cylindrical filter core  43  or it may be any type of commercially available filter. Water flows through the filter and ultimately out of the filter unit through exit  45 . When opening  47  is covered, water from the tap flows around the filter compartment  43  and out of exit  45  without filtering. Thus, water flowing into entrance  53  of the filter unit will either be diverted by switch  46  through the filter compartment  43  and filter  49  or it will flow around filter compartment  43  directly to the exit  45 . Filter unit housing  41  preferably comprises an external switch  42  as a lever to facilitate rotation. In the embodiment of the device depicted, water leaving exit  45  ultimately flows into opening  4  of the measurement unit  3 . However, the device can comprise either the measurement unit  3 , the filter unit  40 , or both. An adapter  54  can be provided to fit the device onto any consumer tap. 
         [0037]    Optionally, an electronic detector can be incorporated into the device to signal when the filter has been activated. For instance, a small magnet coupled to the filter unit and a magnetic sensor coupled to the measurement unit can be used to activate a signal when the filter unit has been rotated into the “on” position. Using the water purity information supplied by the measurement unit, the user can determine when a new filter is needed. When water quality at a tap diminishes and its user is made aware by the device or remote display  51 , the user may desire to install a new water filter.