Abstract:
The invention is an oil-water detection device for monitoring the presence of water in a container. The device consists of a probe having two thin strips of sheeting within a fiberglass circuit board for sensing the presence of water in a container and generating a signal dependent on the presence of water, a divide counter and Stamp II micro-processor and an accessory communications link connected to the micro-processor. A power supply is also provided. The detection device can differentiate between oil and water and will not be activated merely by the presence of oil on the water.

Description:
This is a Continuation of Provisional application Ser. No. 60/096,705, filed Aug. 17, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates generally to the detection of water by electronic means, and more particularly to an electronic probe for detection of occult water or oil in bilges or storage tanks. 
     In the marine and petroleum industries, the detection of water is often necessary to preserve equipment, fuel, and even human lives. 
     As an example, in the marine industry, unwanted water in bilges of ships and other vessels can amount to a lethal hazard if left undetected. History is full of well known instances where rising water in the bilge of a vessel, when undiscovered, has had fatal results and many lives have been lost. In the petroleum and aircraft industries, occult water inside of storage tanks has also had fatal consequences for aircraft and other vehicles where clean fuel is imperative. 
     Prior art devices used in the same context are prone to failure due to a constant off/on cycling as water levels fluctuate with the motion of the vessel, causing the activation float/switch to move with each water movement. This failure is common and potentially lethal. The prior art devices are also prone to running dry once they have pumped all of the available water from the bilge. They also, while pumping all of the water, pump all of the oil and other contaminants into the surrounding water. 
     As one example, a tank field as is usually found at airports, oil refineries, military installations, etc. can cover a vast area with storage tanks in vast numbers. Due to the nature of fuel tanks, in particular, jet fuel tanks where the tank has a floating “lid” designed to prevent the formation of dangerous fumes, rain water tends to leak past the edge seals of the “lids” and into the fuel. In the event that such water finds its way into the fuel tanks of an aircraft, the results are predictably bad. Current technology uses a variety of physical “sounding” methods which employ long wooden rods with a water sensitive coating affixed to one end which is then lowered into the fuel tank where the presence of water can be seen by color change in the coating. This method of detection is physically demanding and inefficient in terms of time and potential for human error. Furthermore, by nature, the fuel tanks often do not have bottoms which are perfectly level, giving rise to the possibility that water could be present but remain undetected by reason of the “sounding” being taken in the wrong place. 
     Use of the instant invention makes possible completely accurate monitoring of even vast tank fields in real time through the use of existing computer networking and satellite uplinks and other existing communications systems. 
     SUMMARY OF THE INVENTION 
     The invention provides a unique means whereby occult water can be detected remotely through the use of a detection probe connected via wires to the detection/signaling electronic circuitry. 
     The invention, in its current form, has at least two configurations both of which rely upon the same electronic circuitry for the detection of water and in one configuration, the circuitry can be connected to a signaling/activation means for controlling a bilge or other pumping device. In the second configuration, the electronic circuitry connects to an electronic measuring means whereby quantitative measurements of occult water can be made and the measurements can be output in a variety of ways such as digital/analog gauges or dials, through remote connection to computers and networks of same or other display or signaling means. 
     The primary element of the instant invention in whichever configuration it may be used, is a special TEFLON coated probe which is the primary detection means. The probe is composed of two thin strips of conductive material held in close proximity to each other. Each of the strips connects via a wire conductive means to an electronic assembly. The function of the electronic assembly is to collect and amplify the minute signal from the probe. The signal is caused to occur whenever the probe is brought into contact with water. The probe senses a change in capacitance which causes the emanation of the signal. Included within the electronic assembly are amplification and calibration circuits which provide a useful operating range and an interface between the device and the operator or monitoring means. 
     As an example, a pre-set calibration allows the probe device to manifest useful features such as alerting to the presence of water and, should the need arise, the automatic activation of a pumping means to remove the water and thereafter automatically deactivating the pumping means once the water returns to a safe level. 
     In actual use, the instant invention constantly monitors the water level present. It ignores the oil which floats upon the water surface and only activates the pumping/signaling means when the water rises to the pre-set level. Once the water level has been reduced to the pre-set level, the device deactivates the pumping means before the floating oil can reach the inlet of the pumping means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG.  1 . is a flow diagram showing the discrete components of the instant invention configured as an “oil-water” detector. 
     FIG.  2 . is a circuit diagram of the main processing of the “oil-water” detector in accordance with the invention. 
     FIG.  3 . is a circuit drawing of the probe component in accordance with the invention. 
     FIG.  4 . is a flow diagram showing the discrete components of the instant invention configured as a bilge pump controller in accordance with the invention, 
     FIG. 5 is a detailed circuit diagram showing the discrete components of the invention configured as a bilge pump controller. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, wherein like numerals designate like and corresponding parts throughout the several views, in FIG. 1 the instant invention, configured as an “oil-water” detector is shown in a flow chart form and is designated overall by the numeral  10 . Probe  11  connects to divide counter  12  and Stamp II micro-controller  13  and display  15 . Outlet connections exit through communication link  14 . Power is supplied through power supply  17  either as a 90 to 240 volt A.C. source or 12 v DC source  19 . The power supply  17 , from whatever source, is regulated and converted as necessary to either +10  mv or  −1O   v. 
     In FIG. 2, the actual circuitry of the oil-water detector  10  is shown in detail. Programming input  20  connects to Stamp II micro-controller  13  and to display  15 . It is enumerated overall by the number  10  to show a corresponding relationship to the flow chart in FIG.  1 . 
     In FIG. 3, the actual circuitry of the oil-water detector probe is shown in detail and designated overall by the numeral  11 . The output interface between the probe  11  and its processing circuitry as shown in FIG. 2, is made via interface  21 . 
     In FIG. 4, the instant invention, configured as a bilge pump controller  30  is shown in a flow chart form. Probe  32  connects to AC amplifier  34  and oscillator  33 , through rectifier time delay  35 , then to DC buffer  36 . Buffer  36  connects to level detection switches  37  and  42  and thence to optocouplers  38  and  43  and FET power amplifiers  39  and  44 . Overload protection is provided by overload protectors  41  and  46 . Final outputs are to alarm outlet  40  and pump outlet  45 . 
     In FIG. 5, the actual circuitry of the oil water processing circuit is shown in detail and designated by the numeral  30 . 
     The oil-water detector  10 , by reason of its sensitivity and its calibration means, can be set to detect even minute amounts of water and can activate and deactivate pumping/signaling means with great accuracy. Its accuracy and operation are unaffected by fouling of the probe  46 . Furthermore, the oil-water detector  10  can be set to read an average water level and to ignore the fluctuations of said level as the vessel moves. By setting the device to activate the pumping/signaling means only when the water level reaches a pre-set level, the device does not thereby constantly activate and deactivate the pumping/signaling means. In the event of a large spill of oil into the bilge which would, with a prior art device, activate the pumping system, the instant device ignores the oil and will not activate the pumping/signaling device unless there is a corresponding rise in the mean water level. This is a unique and useful feature in the context of environmental protection--oil is not pumped overboard. 
     For ease of description, the instant invention in its configuration as a bilge monitoring device has the probe  11  as described above. A controller  13  housed in the main electronic circuitry and an optional indicator panel, display  15  provide a convenient interface between the device and the operator. The functional characteristics of the controller  13  are: 
     Detection of water touching the probe  46 ; 
     Activation of the pumping means; 
     Activation of an alarm system if the water level rises beyond the capacity of the pumping means; 
     Activation of the alarm in the event of a mechanical failure of the cable, pump, or the probe  46  itself; 
     Initiation of a self-test when it is first activated. 
     The indicator panel  15  can be added as an option. While the controller  13  can perform all of its own functions without the indicator panel being present, the addition of the indicator panel  15  provides the operator with a convenient bilge pump control and monitoring system. The indicator panel  15  can be conveniently located near the normal controls of the vessel. In use, the panel  15  uses an LED which is capable of displaying through color changes and intermittency, all conditions and functions of the controller  13  and the pumping means. It is also fitted with a toggle switch by which the system can be switched on and off and between automatic and manual modes. 
     The LED signals the condition of the device in the following manner: 
     When solid green, the system is activated. 
     Flashing green shows the probe is touching water. 
     Flashing yellow shows the pumping means is activated automatically. 
     Red signals that the water is rising above the capacity of the pumping means to reduce the water level and the alarm means is activated. The alarm may be mounted remotely so as to alert people ashore to the presence of danger from the potentially sinking vessel. 
     Yellow means that the pumping means has been manually activated. 
     As shown in FIGS. 4-5, the oil-water detector  10  is capable of differentiating between water and petroleum products and can function either as a device to measure quantities of either. Programming for such diverse functions is possible through an interface which may be connected to a computer operating the unique software program designed as a utility for the instant invention. The circuitry for the probe  11  uses a dual operation amplifier which functions both as an oscillator and as a buffer, and a transistor switch which activates a fixed capacitor. The oscillator is free running and connects to the strips contained within the probe  47 . Due to the fact that water has a different dielectric constant from that of petroleum products, as water rises up the probe  47 , the oscillator frequency changes. The capacitor switch inserts a fixed capacitor across the probe because any failure in any other part of the circuitry would cause an incorrect and thus detectable change. The probe contains a temperature sensing thermister. Physically, the characteristics of the invention differs according to whether it is built as a bilge pump monitor or as a water detection probe. This distinction is made in part by construction of the “probe” component. In the bilge pump configuration, the probe  11  connects to the operational circuitry of the controller via a cable of fixed and predetermined length--such being a necessary component in the calibration of the device. Conversely, when constructed as an “oil-water” detector, the probe  11  contains within it a part of its detection circuitry which is then connected by a cable of no fixed length to the master circuitry. This design enables the “oil-water” detector  11  to be used within tanks of varying depths and varying distances from a monitoring station without the restraint of having to be within a close proximity to the monitoring system. 
     In a preferred embodiment, the special probe  11  consisted of two thin strips of copper sheeting within a fiberglass circuit board (probe  47 ) and was contained within a molded, outer cover of synthetic flourine-containing resins (TEFLON) as a protection and anti-fouling device. 
     In operation, the circuitry performs the following functions: 
     The frequency signal from the probe  11  is divided by  10 , then applied to a Stamp II micro controller  13  which measures the frequency, applies corrections to it and visually displays the actual water depth detected by the probe  11 . The Stamp II micro controller  13  then activates a test switch and recounts the frequency, again applying corrections to it. Results of the test are then displayed as an indication of the overall operation of the circuitry of the device. The scope of the second configuration encompasses a vast array of possible uses and application by reason of its unique circuitry and the versatility of the probe component. 
     Thus it will be appreciated that the present invention provides a new and novel oil-water detector which can be used in many environments including water or oil. It is contemplated that other embodiments and/or modifications may be made in the present invention without departure from inventive concepts manifested by the disclosed embodiments. It is expressly intended, therefore, that the foregoing description is illustrative only of preferred embodiments, not limiting, and that the true spirit and scope of the invention be determined by reference to the appended claims.