The present invention relates to faucets of the type used in sinks, lavatories, urinals and the like. Typically these faucets are made from metal or plated plastics and are electrically conductive. A module affixed to the outlet end of the faucet senses temperature or other fluid properties and generates a signal. A valve controller receives the generated signal and positions a control valve accordingly. The generated signal is communicated from the module to the valve controller by passing the signal along the conduit itself.

FIELD OF THE INVENTION 
     The present invention relates to faucets and retrofit systems for faucets, and more particularly to faucet and retrofit systems that monitor and control fluid properties of dispensed fluids. 
     BACKGROUND OF THE INVENTION 
     There are several faucets and retrofit systems available that monitor fluid temperature of fluid flowing out of the faucet, and that provide some level of control over the flow of fluid out of the faucet, based on the temperature monitored. 
     Systems include those described in Canadian Patent Application 2,162,802 (Zosimadis) and in U.S. Pat. No. 5,184,642 (Powell). 
     Such systems use sensors to measure fluid temperature, a valve controller and valve, where the valve controller actuates the valve based on the temperature of the fluid, and a means for sending information from the sensors to the valve controller. Because the sensors for the fluid properties are sometimes located remotely from the valve and valve controller, a transmitter is usually located at the sensors, and a receiver is usually located at the valve controller. 
     The transmitters and receivers disclosed in the prior art communicate with each other, either along wires that extend between them, or by radio frequencies or other ‘through-the-air’ means, usually referred to as wireless systems. 
     Although these systems are effective in monitoring fluid temperature, they have drawbacks that hamper their marketability. For example, the systems that use a wired connection on the faucet may be viewed as a high risk for electrocution by consumers. Alternately, wireless systems that communicate by radio frequency or the like, can be bulky, unattractive and expensive to manufacture. 
     Consequently, there is a need for a system to provide fluid monitoring and flow control, which is aesthetically pleasing and economical. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a faucet including an electrically conductive fluid outlet conduit, an electrical transmitter that is connected electrically with the outlet conduit, one or more valves for controlling the flow of fluid through the outlet conduit, a valve controller for changing the position of the valve(s), the valve controller including a receiver that is connected electrically with the outlet conduit, the valve controller being adapted for receiving electrical signals from the transmitter, and wherein the electrical signals are communicated from the transmitter to the receiver through the outlet conduit. 
     In another aspect of the invention, the invention involves a kit of parts for retrofit to an existing faucet with an electrically conductive fluid outlet conduit. The kit of parts comprises an adaptor, which comprises at least one sensor and a transmitter, which is to be connected electrically with the outlet conduit, the transmitter being adapted to transmit electrical signals through the outlet conduit, at least one control valve for controlling the flow of fluid through the outlet conduit, and a valve controller for changing the position of the control valve, the valve controller further comprising an electrical signal receiver for receiving electrical signals through the outlet conduit, the electrical signal receiver connected electrically with the outlet conduit. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the invention may now be appreciated from reviewing the following descriptions of preferred embodiments of the invention, and in which: 
     FIG.  1 —is a schematic view of a faucet in accordance with a preferred embodiment of the present invention; 
     FIG.  2 —is a block diagram of an adaptor for use with the faucet shown in FIG. 1; 
     FIG.  3 —is a block diagram of a valve controller for use with the faucet shown in FIG. 1; 
     FIG.  4 —is a front elevation view of a double-valve faucet in accordance with another preferred embodiment of the present invention; 
     FIG. 4 a —is a side elevation view of the faucet shown in FIG. 4; 
     FIG.  5 —is a block diagram of an adaptor for use with the faucet shown in FIG. 4; 
     FIG.  6 —is a block diagram of a valve controller for use with the faucet shown in FIG. 4; 
     FIG.  7 —is a schematic view of a single-valve faucet which can be adapted in accordance with embodiments in accordance with the present invention; 
     FIG.  8 —is a schematic view of a kit of parts in accordance with another preferred embodiment of the present invention, for retrofit to an existing single-valve faucet; 
     FIG.  9 —is a schematic view of the single-valve faucet with the kit of parts of FIG. 8; 
     FIG.  10 —is a front elevation view of a double-valve faucet which can be adapted in accordance with embodiments in accordance with the present invention; 
     FIG.  11 —is a front elevation view of a kit of parts in accordance with another preferred embodiment of the present invention, for retrofit to an existing double-valve faucet; 
     FIG.  12 —is a front elevation view of a double-valve faucet with the kit of parts of FIG. 11; 
     FIG. 12 a —is a side elevation view of the faucet shown in FIG. 12; 
     FIG.  13 —is a front elevation view of kit of parts in accordance with another preferred embodiment of the present invention, for retrofit to an existing double-valve faucet; 
     FIG.  14 —is a front elevation view of a double-valve faucet with the kit of parts of FIG. 13; 
     FIG. 14 a —is a side elevation view of a the faucet shown in FIG. 14; 
     FIG.  15 —is a block diagram of an alternative valve controller for use with a single-valve faucet in accordance with another preferred embodiment of the present invention; and 
     FIG.  16 —is a front elevation view of a grouping of faucets according to an alternate embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A simple, preferred embodiment of the present invention is shown in FIG. 1. A faucet  10  comprises a fluid supply conduit  12 , a control valve  14 , a fluid outlet conduit  16 , an adaptor  18  and a valve controller  20 . Faucet  10  is defined for the purposes in this disclosure and claims to include but is not limited to: a kitchen faucet, a lavatory faucet, a bar faucet, a utility faucet, a shower faucet, a tub faucet, a roman faucet, a washbasin, a urinal, and a toilet. 
     Faucet  10  carries fluid from a fluid supply (not shown), and discharges the fluid. The fluid path through faucet  10  is from fluid supply (not shown), through supply conduit  12 , through control valve  14 , through outlet conduit  16 , through adaptor  18 , and out. 
     Control valve  14  controls the flow of fluid from supply conduit  12  into outlet conduit  16  and may be any valve known in the art that is electrically operated and can seal against liquid flow. Outlet conduit  16  is made from an electrically conductive material, such as an electrically conductive metal or polymer. For example, the outlet conduit  16  may be made from brass, copper, stainless steel, alloy steel, or chrome plated plastic. Outlet conduit  16  has an inlet end  22  and an outlet end  23 . At the outlet end  23  of outlet conduit  16  is mounted adaptor  18 , and at the inlet end  22  is mounted control valve  14  with valve controller  20 . 
     As shown in FIG. 2, adaptor  18  includes an adaptor power module  30 , a plurality of power connectors  31 , at least one sensor  32  for sensing fluid properties, a plurality of signal connectors  33 , an adaptor processor  34 , an adaptor input module  36 , and an adaptor transmitter  40 . In this embodiment, outlet end  23  of outlet conduit  16  is threaded and adaptor  18  is threaded with a matching thread, and adaptor  18  is threaded onto the outlet end  23  of outlet conduit  16 , thereby physically and electrically connecting outlet conduit  16  and adaptor  18 . However, adaptor  18  may be mounted in any way such that transmitter  40  is in electrical communication with outlet conduit  16  and such that sensors  32  are located to sense the desired fluid properties. 
     Sensors  32  detect fluid properties such as PH, temperature, conductivity, clarity, and levels of chlorine, bacteria, pesticide, cysts, protozoa, fecal matter, lead, silt, rust, asbestos or other sediments, calcium, ammonia, nitrites, and nitrates. Any other fluid properties known in the art may be sensed as well. If only one fluid property is to be sensed only one sensor would be required. If a plurality of properties are to be sensed then a plurality of sensors may be employed. Sensors  32  communicate fluid property data to adaptor processor module  34  through signal connectors  33 . Signals sent between individual components of adaptor  18  are sent through a plurality of signal connectors  33 . 
     Adaptor input module  36  is used to enable a user to input desired parameters to adaptor  18 , including maximum and minimum acceptable fluid property values (safety limits), such as maximum and minimum fluid temperatures. As well, adaptor input module  36  may provide means for a user to initiate fluid flow, and to set the desired volume flow of fluid from faucet  10 . Processor module  34  processes fluid property data received from sensors  32  to determine if any detected properties exceed specified safety limits. Based on the inputted parameters and the detected fluid properties, adaptor processor  34  sends signals  63  to valve controller  20  through adaptor transmitter  40 . In this embodiment, signals  63  correspond to valve position (i.e. “Open Valve” and “Close Valve”) commands. Power module  30  provides power to all required components in adaptor  18 , through power connectors  31 . Power module  30  preferably comprises a battery, but may be any other self-contained power source known in the art. Signal connectors  33  and power connectors  31  may be joined together in a single connector. Power, in this embodiment, is transferred in a combination of serial and parallel routes to the required components of adaptor  18 , however, the power may be transferred by any means known in the art. 
     Adaptor  18  may further include a user-override switch  844  in input module  36 , a user-detector sensor  848 , an output module  849  that may include an alarm  851 , and an electrical signal receiver  870  for.receiving signals  873 . All of these items will be discussed further below. 
     Valve controller  20 , shown in FIG. 3, actuates control valve  14  based on the signals  63  received from adaptor  18 . Valve controller  20  includes a valve controller power module  50 , a valve actuator  52 , which actuates valve  14 , a valve controller receiver  62 , a plurality of power connectors  31 , and a plurality of signal connectors  33 . Power module  50  provides power to all required components of valve controller  20  through power connectors  31 . Power module  50  is itself preferably a connection to a DC power source, such as a battery, but may alternately comprise a connection to an AC power source or any other power source known in the art. Power, in this embodiment, is transferred in a combination of serial and parallel routes to the required components, however it may be transferred by any means known in the art. 
     Valve controller receiver  62  receives signals  63  from adapter  18  and passes the signals  63  on to valve controller actuator  52 . In the embodiment shown in FIG. 1, receiver  62  is attached to outlet conduit  16 , by means of welds. Receiver  62  may, however, be located in any way such that it is in electrical communication with outlet conduit  16 . For example, receiver  62  may be bolted to outlet conduit  16 . Alternately, if control valve  14  is made from a conductive material and is in electrical communication with outlet conduit  16 , then receiver  62  may be mounted on control valve  14 , such that receiver  62  and control valve  14  are in electrical communication with each other. Signals sent between individual components of valve controller  20  are sent through signal connectors  33 . Signal connectors  33  and power connectors  31  may be joined together in a single connector. 
     In this embodiment, adaptor  18  and valve controller  20  operate such that, in the event that adaptor  18  determines that a detected fluid property exceeds a specified limit, adaptor transmitter  40  sends a signal  63  to valve controller receiver  62 , indicating for valve controller  20  to close control valve  14 . Signals  63  sent between transmitter  40  and receiver  62  are sent through electrically conductive outlet conduit  16 . 
     The electrical signal path  64 , through which signals  63  are sent between adaptor  18  and valve controller receiver  62 , is schematically illustrated in FIG.  1 . The electrical signal path does not use wires and is not wireless as that term is conventionally used. Rather, the signal path  64  is through the electrically conductive fluid outlet conduit to which the adaptor  18  and the controller  20  are electrically connected. The signals sent may correspond to the following: “Open control valve  14 ”, “Close control valve  14 ”, and one or more fluid properties. The sending of fluid property data signals will be discussed further below. 
     FIGS. 4,  4   a ,  5  and  6  show an alternate embodiment of the present invention. Referring to FIGS. 4 and 4 a , faucet  100  includes a first fluid supply conduit  112 , a second fluid supply conduit  212 , a first fluid control valve  114 , a second fluid control valve  214 , a valve controller  120 , a tee  128 , an outlet conduit  116 , and an adaptor  118 . Supply conduits  112  and  212  carry to faucet  100 , first and second fluids respectively, from first and second fluid supplies respectively (not shown). Control valves  114  and  214  are similar to control valve  14  except that they are designed such that they may be opened fully, closed fully, or opened partially, thus allowing a range of partial flows of fluid through them. Control valves  114  and  214  connect to supply conduits  112  and  212  respectively. Tee  128  connects at its two inlets to control valves  114  and  214  and at its outlet, to inlet end  122  of outlet conduit  116 , as shown. 
     Similar to the embodiment in FIG. 1, in this embodiment the outlet end  123  of outlet conduit  116  is threaded and adaptor  118  is threaded with a matching thread, and adaptor  118  is threaded onto the outlet end  123  of outlet conduit  116 , thereby connecting outlet conduit  116  with adaptor  118 . However, adaptor  118  may be mounted in any way such that transmitter  140  is in electrical communication with outlet conduit  116  and such that sensors  132  are located to sense the desired fluid properties. 
     Referring now to FIG. 5, adaptor  118  is similar to adaptor  18  with the following differences. Adaptor  118  includes an adaptor processor  134  instead of adaptor processor  34 . Adaptor processor  134  is adapted to send valve command signals  163  to operate two valves. Adaptor input module  136  is similar to adaptor input module  36  but is further adapted to receive a target value for any fluid property that differs between the two fluids. For example, if the two fluids are hot and cold water, the fluid property that differs between them is temperature, and the target value that can be entered into input module  136  will therefore be a specified temperature of the dispensed water. 
     Referring now to FIG. 6, valve controller  120  includes a power module  150 , a plurality of power connectors  131 , a plurality of signal connectors  133 , valve actuators  152  and  252  for actuating control valves  114  and  214  respectively, a processor module  154  for processing received signals  163  and for sending valve actuation signals to valve actuators  152  and  252 , and a valve controller receiver  162  for receiving signals  163  from adaptor  118 . 
     Valve controller  120  can position control valves  114  and  214  independently, into fully open or closed, or partially open states, thus allowing only a first fluid to flow, or only a second fluid to flow, or allowing a desired mixture ratio of the two fluids to flow. Power module  150  powers all required components of valve controller  120 , through power connectors  131 . Signals sent between individual components of valve controller  120  are sent through signal connectors  133 . Signal connectors  133  and power connectors  131  may be joined together in a single connector. 
     Valve controller  120  may further comprise an input module  856 , an output module  858 , and a valve controller transmitter  872  for transmitting electrical signals  873 . All of these items will be discussed below. 
     If the desired fluid property, as sensed by adaptor  118 , strays from the specified target value, the position of one or both of control valves  114  and  214  is adjusted in order to adjust the ratio of the first fluid and the second fluid, in order to maintain the fluid property value at or substantially at its target value. Preferably, in the event that the sensed fluid property strays by more than a specified ‘adjustment-causing’ amount, then the valve controller will adjust both control valves  114  and  214 , increasing the flow through one valve and decreasing the flow through the other valve each by a predetermined amount, so as to maintain roughly the same fluid flow rate through outlet conduit  116 . If any fluid property, however, exceeds specified safety limits, valve controller  120  will close control valves  114  and  214 . 
     An electrical signal path  164 , through which signals  163  are sent between adaptor  118  and valve controller receiver  162 , is schematically illustrated in FIG. 4 a . The signal path  164  is through the outlet conduit  116  to which the adaptor  118  and the controller receiver  162  are electrically connected. 
     The signals sent may correspond to the following valve commands: “Open both control valves”, “Close both control valves”, “Increase flow in one control valve and decrease flow in the other control valve by a predetermined amount” or one or more fluid properties. Due to the increased complexity in the nature of the signals sent between the adaptor and the receiver, relative to the simple embodiment described above, both the adaptor processor and the valve controller processor will require additional means for ensuring that the signals are intelligible at the receiver. This will be discussed further below. 
     Another alternate embodiment of the present invention, as shown in FIGS. 8 and 9, is a kit of parts  350  for retrofit onto an existing single-valve faucet  300 , shown in FIG.  7 . Faucet  300  includes a supply conduit  312 , that carries fluid to an outlet conduit  316 . Outlet conduit  316  includes a hand valve  304 . Outlet conduit  316  has an inlet end  322 , which is upstream of hand valve  304  and which is connected to supply conduit  312 . Outlet conduit  316  also has an outlet end  323 , which is usually threaded. Hand valve  304  includes a hand actuator  302 , which may be a hand knob, a mechanical push button or any other actuation means known in the art. Outlet conduit  316  must comprise at least enough conductive material such that an electrically conductive path exists between inlet end  322  and outlet end  323 . Supply conduit  312  joins outlet conduit  316  at inlet end  322 . 
     As shown in FIG. 8, the kit of parts  350  includes a valve conduit  306 , control valve  314 , an adaptor  318 , and valve controller  320 . Valve conduit  306  mounts to inlet end  322  of outlet conduit  316 , and is manufactured from a conductive material, such as brass, copper, stainless steel, alloy steel, or chrome plated plastic. Attached to the upstream end of valve conduit  306  is control valve  314 . 
     Adaptor  318  is similar to adaptor  18  except that adaptor  318  is adapted for mounting to outlet end  323  of existing outlet conduit  316 . Similar to the embodiments described above, the outlet end  323  of outlet conduit  316  may be threaded and adaptor  318  may be threaded with a matching thread, and adaptor  118  is threaded onto the outlet end  323  of outlet conduit  316 , thereby connecting outlet conduit  316  with adaptor  318 . However, adaptor  318  may be mounted in any way such that a transmitter similar to transmitter  40 , is in electrical communication with outlet conduit  316  and such that sensors similar to sensors  32 , are located to sense the desired fluid properties. Valve controller receiver  362  may be mounted on conduit  306  as shown, or alternately may be mounted in any way such that it is in electrical communication with outlet conduit  316 . 
     FIG. 9 shows the kit of parts  350  installed on faucet  300 . An electrical signal path  364 , through which signals  363  (not shown) can be sent between adaptor  318  and valve controller receiver  362 , is shown schematically in FIG.  9 . 
     Another alternate embodiment of the present invention, as shown in FIGS. 11,  12  and  12   a , is a kit of parts  450  for retrofit to a double-valve faucet  400  shown in FIG.  10 . Faucet  400  includes an outlet conduit  416 , a first supply conduit  412 , and a second supply conduit  512 . Outlet conduit  416  includes an internal tee  428  for receiving fluid from two sources, and hand valves  404  and  504  which connect to the upstream ends of internal tee  428 . Outlet conduit  416  has two inlet ends  422  and  522  which are upstream of valves  404  and  504  respectively, and an outlet end  423  that is usually threaded. Hand valves  404  and  504  include hand actuators  402  and  502 . Hand actuators  402  and  502  may be hand knobs, mechanical push buttons or any other actuation means known in the art. Outlet conduit  416  must comprise at least enough conductive material such that an electrically conductive path exists between outlet end  423 , and at least one of inlet ends  422  and  522 . Supply conduits  412  and  512  carry to faucet  400 , first and second fluids respectively, from first and second fluid supplies respectively (not shown). Supply conduits  412  and  512  connect to inlet ends  422  and  522  respectively, of outlet conduit  416 . 
     As shown in FIG. 11, kit of parts  450  includes valve conduits  406  and  506 , control valves  414  and  514 , an adaptor  418 , and valve controller  420 . FIGS. 12 and 12 a  show the kit of parts  450  installed on faucet  400 . Valve conduits  406  and  506  mount to the inlet ends  422  and  522  of outlet conduit  416 , and are manufactured from a conductive material, such as, brass, copper, stainless steel, alloy steel, or chrome plated plastic. At least one of valve conduits  406  and  506  must be connected such that it is in electrical communication with outlet end  423  of outlet conduit  416 . Attached to the upstream ends of valve conduits  406  and  506  are control valves  414  and  514 , which are similar to control valves  114  and  214 . 
     Adaptor  418  is similar to adaptor  118 , except that adaptor  418  is adapted for fitting onto the outlet end  423  of outlet conduit  416 . Similar to the embodiments described above, the outlet end  423  of outlet conduit  416  may be threaded and adaptor  418  may be threaded with a matching thread, and adaptor  418  is threaded onto the outlet end  423  of outlet conduit  416 , thereby connecting outlet conduit  416  with adaptor  418 . However, adaptor  418  may be mounted in any way such that an adaptor transmitter similar to transmitter  40  is in electrical communication with outlet conduit  416  and such that sensors similar to sensors  32  are located to sense the desired fluid properties. A valve controller receiver  462  is included in kit of parts  450 , and may be mounted directly to one of valve conduits  406  and  506 , such that receiver  462  is in electrical communication with outlet conduit  416 . Receiver  462  may, however, be located in any way such that it is in electrical communication with outlet conduit  416 . 
     An electrical signal path  464 , through which signals  463  (not shown) can be sent between adaptor  418  and valve controller receiver  462 , is shown schematically in FIG. 12 a.    
     Another alternative embodiment of the present invention, as shown in FIGS. 13,  14  and  14   a , is another kit of parts  650  for retrofit to double-valve faucet  400  as shown in FIG.  10 . In this embodiment, double-valve faucet  400  is converted such that both hand actuators  402  and  502  cause fluid of the same temperature to dispense. As shown in FIG. 13, the kit of parts  650  includes a control valve  614  which is similar to control valves  314  and  14 , an adaptor  618 , a valve controller  620 , an upstream tee  628 , and a downstream tee  728 . FIGS. 14 and 14 a  show the kit of parts  650  installed on faucet  400 . Downstream tee  728  connects to inlet ends  422  and  522  of outlet conduit  416 . Downstream tee  728  is made from a conductive material, such as, brass, copper, stainless steel, alloy steel, or chrome plated plastic. Downstream tee  728  must be connected such that it is in electrical communication with outlet end  423  of outlet conduit  416 . Attached to the upstream end of downstream tee  728  is control valve  614 . A valve controller receiver  662  is included in kit of parts  650 , and may be mounted directly to downstream tee  728 , such that it is in electrical communication with outlet conduit  416 . Receiver  462  may, however, be located in any way such that it is in electrical communication with outlet conduit  416 . Upstream tee  628  connects to control valve  614 , and supply conduits  412  and  512  connect to upstream tee  628 . 
     In order to prevent fluid from flowing from supply conduit  412 , through upstream tee  628 , and into supply conduit  512  (or in the reverse path, from conduit  512 , through tee  628 , and into conduit  412 ) due to a pressure differential in conduits  412  and  512 , check valves are located within upstream tee  628 , just downstream of the upstream ends of upstream tee  628 . These check valves permit flow into upstream tee from either supply conduit  412  or  512 , but only permit fluid to discharge from the downstream end of tee  628 . 
     Adaptor  618  is similar to adaptors  318  and  18  except that adaptor  618  is adapted for mounting to outlet end  423  of existing outlet conduit  416 . Similar to the embodiments described above, the outlet end  423  of outlet conduit  416  may be threaded and adaptor  618  may be threaded with a matching thread, and adaptor  618  is threaded onto the outlet end  423  of outlet conduit  416 , thereby connecting outlet conduit  416  with adaptor  618 . However, adaptor  618  may be mounted in any way such that an adaptor transmitter similar to transmitter  40 , is in electrical communication with outlet conduit  416  and such that sensors, similar to sensors  32 , are located to sense the desired fluid properties. 
     An electrical signal path  664 , through which signals  663  (not shown) are sent between adaptor  618  and valve controller receiver  662 , is shown schematically in FIG. 14 a.    
     A user-override switch  844  may further be included on the adaptor input modules  36 ,  136  for any of the adaptors described above, as shown in FIGS. 2 and 5. User-override switch  844  prevents the control valves from being closed in the event of a fluid property exceeding a specified value. This may be accomplished at the adaptor processor so that the adaptor processor only sends signals to the valve controller if user override switch  844  is off. Alternately, user-override switch  844  may open a circuit, preventing sensor data signals from reaching the adaptor processor from the sensors. 
     Each of the adaptors disclosed above may further include a user-detector sensor  848 , as shown in FIGS. 2 and 5. User-detector sensor  848 , upon detection of a user, sends a signal to the adaptor processor. Upon receipt of the signal indicating that a user is present, the adaptor sends a signal to the valve controller. In a lavatory, for example, the detection of a user will trigger the system to open the control valves, and when the user is no longer detected, the system will close the control valves. In a urinal or a toilet, however, the presence of a user will trigger the system to wait until the user is no longer detected, and then, when the user is no longer detected (ie. the user has moved away from the urinal or toilet), to open the control valve for a set ‘flushing cycle’ period of time. 
     As well, systems equipped with user-detector sensor  848 , can operate such that the adaptor only sends signals to the valve controller when a user is present. In this way, battery power in the adaptor is conserved, since the power consumed in operating user-detector sensor  848  continuously, is smaller than the power consumed in transmitting signals continuously between an adaptor and a valve controller. 
     User-detector sensor  848  may be any type known in the art, such as a proximity sensor, a mechanical switch, an ultrasonic emitter, an infra-red beam, or a passive infra-red detector. 
     A pressure sensor may be included as one of the plurality of sensors in the adaptor to provide an alternate way of conserving battery energy in the adaptor, instead of user-detector sensor  848 . When the pressure sensor detects atmospheric pressure in the outlet conduit, indicating that there is no fluid flow in the outlet conduit, the adaptor is prevented from sending signals to the receiver. When a user initiates fluid flow by means of the input module on the adaptor or by means of a hand valve, and fluid flows through the outlet conduit, then the pressure sensor will sense a pressure increase from the fluid flow, indicating to the adaptor to send signals to the receiver. 
     Any of the above described adaptors may further include an output module  849 , as shown in FIGS. 2 and 5. Output module  849  indicates fluid property data and may further indicate the status of certain elements of the system, such as ‘user-detected’, ‘user-override ON’, battery strength, system fault condition, specified fluid property limit values, and/or whether a fluid property has exceeded the specified safety limits. Output module  849  may be a visual display, such as an LCD or an LED device, and/or an audio device. Output module  849  may further include an alarm  851  which indicates to a user visually and/or audibly whether a fluid property has exceeded a specified limit. 
     Single-valve faucet  10 , illustrated in FIG. 1, may alternately include a valve controller  20 ′, shown in FIG. 15, instead of valve controller  20 . Valve controller  20 ′ is similar to valve controller  20 , with the following differences. Valve controller  20 ′ includes a valve controller processor  854  that can determine control valve actuation required, based on data received. Therefore, valve controller  20 ′ is adapted to respond to signals  63  that correspond with fluid property data and other data obtained from sensors  32 ,  848 , and user input from input module  36 . In this embodiment, valve controller receiver  62  sends received signals  63  to valve controller processor  854  that processes the signals  63  and determines the appropriate control valve actuation required. Processor  854  controls control valve  14  through valve actuator  52 . Valve controller  20 ′ may also include a valve controller input module  856  and a valve controller output module  858 . Input module  856  and output module  858  may operate similarly to input module  36  and output module  849  respectively. Similarly, valve controller  120  may further include input module  856  and output module  858 . 
     Retrofit kit of parts  350  may include a valve controller modified in a manner similar to valve controller  20 ′, instead of valve controller  320 . Similarly, retrofit kit of parts  650  may include a valve controller modified in a manner similar to valve controller  20 ′, instead of valve controller  620 . 
     For any of the adaptors described above wherein the adaptor comprises only one sensor, the adaptor may not require an adaptor processor, adaptor input module  36  and adaptor output module  849 . In this example, the lone sensor will transmit signals directly to the adaptor transmitter. The valve controller receiving the signals must therefore include a valve controller processor, similar to valve controller  20 ′,  120 , and  420  and a valve controller input module  856 , and may include a valve controller output module  858 , as shown FIGS. 6 and 15. In this case, the valve controller processor receives fluid property data from the adaptor and input data from the input module  856 , and determines the appropriate valve actuation that is required. In all cases where the adaptor includes two or more sensors, however, the adaptor advantageously includes a processor to coordinate the sending of signals to the valve controller. In all cases where an adaptor sends more than one signal to the valve controller, both the valve controller and the adaptor require a processor. This may comprise fluid property data signals from two or more sensors, or alternately, this may comprise valve commands for two or more valves. 
     Each of the valve controllers that include a valve controller processor may further include a valve controller transmitter  872 , and each of the adaptors disclosed above may further include an adaptor receiver  870 . The valve controller, in response to receiving a signal from the adaptor, may transmit an acknowledgement signal  873  back to adaptor receiver  870  acknowledging receipt of the original signal. Upon sending a signal  63 , and waiting for a specified period of time, the adaptor can flag a fault condition if it does not receive an acknowledgement signal  873  back from the valve controller. Upon determining that a fault condition exists, indication may be made in output module  849 , alarm  851  may be signalled, and the valve controller may instruct one or more control valves to close or to change position. 
     If both the adaptor and the receiver of a faucet or kit of parts in accordance with the present invention, possess a processor, then signals sent between the adaptor and receiver may be digital or analog signals. If either the adaptor or the receiver does not include a processor, then the signals must be analog signals. 
     FIG. 16 depicts various faucets grouped, for example in a restaurant washroom. Faucet  10   a  includes adaptor  18   a , which includes transmitter  40   a  (not shown), and which sends signals  63   a  (not shown) along electrical signal path  64   a  to receiver  62   a . Similarly, faucet  10   b  includes adaptor  18   b , which includes transmitter  40   b  (not shown), and which sends signals  63   b  along electrical signal path  64   b  to receiver  62   b , and so on. In this scenario, signals  63   a  sent from adaptor  18   a  on faucet  10   a  will be received by receivers  62   a , and there is a risk that these signals may also be received by receivers  62   b ,  62   c ,  62   d  . . .  62   n  on other faucets that happen to be in electrical communication with transmitter  40   a , through supporting structures, countertops, or piping for example, a phenomenon known as cross-talk. In order to prevent cross-talk, (ie. receivers  62   b-   62   n  from receiving the signals  63   a  from transmitter  40   a ), an isolator  880  may be installed to electrically isolate electrical signal path  64   a . Isolator  880  must be installed at some point outside of electrical signal path  64   a . Isolator  880  is made from a non-conductive, liquid-impermeable material, such as rubber. In the embodiment shown in FIG. 16, isolator  880  is shown in the form of a spool piece of conduit between control valves  14   a - 14   n  and supply conduits  12   a - 12   n . Alternately, isolator  880  may be in the form of a washer that separates control valve  14   a-n  from outlet conduit  16   a-n.    
     In the example shown in FIG. 16, the faucets shown are single-valve faucets, functionally similar to those in the embodiment of FIG. 1, however, isolator  880  may be used to prevent cross-talk in groupings of any of the different faucets described above. In some instances, two or more isolators  880  may be required in order to isolate the electrical signal path between adaptor and receiver, for example, for two valve faucets. 
     In the case where the structure surrounding a faucet according to an embodiment of the present invention, is composed of an electrically conductive material, and the surrounding structure is in electrical communication with the above described electrical signal paths, an isolator layer can be installed to isolate the above described electrical signal paths. 
     As an alternate way of preventing the reception and action based on neighbouring or other stray signals travelling along the electrical path, any of the transmitters described in the embodiments above may add identification codes to signals sent out, such that signals sent between the transmitters and receivers include the identification code. Each individual transmitter produced can be provided with a code that is unique. The code is used to indicate to the receiver the source of the signal received. In this way, the processor that is processing the received signal is adapted to only act upon signals that include the expected identification code, so that stray signals received, are ignored. Alternately, each individual transmitter/receiver pair may be produced so that they operate on a specific frequency. Therefore, the receiver is adapted to only pass on signals sent at the appropriate frequency. 
     Means, as described above, of isolating signal paths, or of adding identification codes to signals or frequency encoding signals are not required, if electrical signal paths  64   a-n  are isolated inherently by the components of faucet  10   a-n , or if For example, supply conduits  12   a-n , may be made from a non-conductive material, and will therefore inherently isolate electrical signal path  64   a-n.    
     In all of the kits of parts described above, valve conduits may not be required, if the control valves and isolators (if the isolators are required) that are included in the kits can be directly connected to the outlet conduits of the existing faucets. 
     Utilizing an outlet conduit as an electrical conduit between a transmitter and a receiver provides an inexpensive, aesthetically appealing, robust, power saving, long-range, interference-free means of communicating signals. Also, the system avoids the use of sophisticated and expensive wireless means and unsightly, dangerous wired means. Furthermore, the system can be readily adapted or retro-fitted onto existing faucets simply and easily or may be pre-installed onto a faucet at the factory. 
     As will be apparent to persons skilled in the art, various modifications and adaptations of the structures described above are possible without departure from the present invention, the scope of which is defined in the appended claims.