Combination water contaminant and fuel density detector

Claim 2

A water/fuel density detector for a fuel tank or the like comprising, in combination, a longitudinally extending light-transmitting body adapted to be disposed within a fuel tank in an upstanding position with the bottom end of said body adjacent the bottom of said tank, said body having a substantially vertically extending side face forming an interface with the fluid in said tank, light-emitting means on the bottom end of said body for transmitting emitted light to said interface in the form of a group of divergent rays in angularly disposed light emission paths, said rays having successively increasing angles of incidence upwardly with respect to said interface, a plurality of vertically spaced light sensors mounted on an opposite side face of said body, each of said light sensors being arranged in optical communication with the light reflection paths of a respective one of said rays, said sensors being responsive to the reflected rays whose angle of incidence exceeds the critical angle corresponding to the index of refraction of said fluid in accordance with Snell's Law and non-responsive to said rays whose angle of incidence is below said critical angle and are thereby refracted into said fluid, detection means connected to said light sensors for detecting the dark-light boundary between said responsive and non-responsive sensors to produce an output signal corresponding to the index of refraction and therefore to the density of said fluid said light-emitting means being arranged to transmit an angularly disposed supplemental ray of emitted light having a terminus on said interface adjacent the bottom end of said body, said supplemental ray having an angle of incidence corresponding to at least the critical angle of water whereby said supplemental ray is reflected by the presence of water at said supplemental ray terminus, and a supplemental light sensor on said body opposite said side face arranged in optical communication with the reflection path of said supplemental ray for response to said reflected supplemental ray and wherein said detection means is connected to said supplemental light sensor for detecting the response of said supplemental light sensor to provide an output signal indicative of the presence of water at a level on said interface corresponding to said supplemental ray terminus.

Claim 3

A water/fuel density detector in accordance with claim 1 wherein the angle of incidence of the lowermost ray in said group of rays is at at least the critical angle corresponding to the index of refraction for water as said fluid whereby said lowermost ray is reflected by the presence of water at a level on said interface coincident with the terminus of said lowermost ray on said interface for response by the light sensor in the light reflection path of said lowermost ray.

Claim 4

A water/fuel density detector in accordance with a claim 1 including means for separating the light emission and the light reflection paths of said group of rays from the light emission and the light reflection paths of said supplemental ray.

Claim 5

A water/fuel density detector in accordance with claim 1 wherein said plurality of sensors include at least one light sensor on the upper end of said body in optical communication with the light reflection path of at least the uppermost ray in said group of rays.

Claim 6

A water/fuel density detector in accordance with claim 1 wherein said light-emitting means includes a pair of lamps mounted on said body bottom end, the output of one of said lamps providing said group of divergent rays and the output of the other of said lamps providing said supplemental ray and means for connecting said pair of lamps to an associated source of electrical power.

Claim 7

A water/fuel density detector in accordance with claim 5 including an inwardly directed, angularly disposed notch having a non-reflective surface in said body between said pair of lamps for occluding light in said light emission path of said supplemental ray from said plurality of light sensors and an inwardly directed notch having a non-reflective surface in said interface adjacent said body bottom end for occluding light in said light reflecttion path of said supplemental ray from said plurality of light sensors.

Claim 8

A water/fuel density detector in accordance with claim 6 including an inwardly directed notch having a non-reflective surface in said body opposite side face for occluding light in said light emission paths of said group of divergent rays from said supplemental light sensor.

Claim 9

A water/fuel density detector in accordance with claim 7 wherein said light-transmitting body includes a necked-down upper portion forming a ledge having a corner on said opposite side face and wherein said supplemental light sensor is disposed on said ledge.

Claim 10

A water/fuel density detector in accordance with claim 8 including an inwardly directed notch having a non-reflective surface on the opposite side face of said necked-down portion for occluding light in the light emission paths of said group of divergent rays from the upper end of said body.

Claim 11

A water/density detector for a fuel tank or the like comprising, in combination, an elongated light-transmitting body adapted to be disposed within a fuel tank in an upstanding position with the lower portion of said body adjacent the bottom of said tank, said body having a side face forming an interface with the fluid in said tank, said body having a plurality of internal reflection areas adjacent a marginal edge of said body, light-emitting means on said body for transmitting emitted light in the form of a group of divergent rays within said body onto said interface in a plurality of regularly disposed light emission paths, a plurality of light sensors mounted on said body in optical communication with the light reflection paths of said rays reflected from said interface within said body, some of said sensors being adapted to respond only to rays reflected from said interface for indicating the absence of fluid at spaced apart locations on said interface from which said rays are reflected, other of said sensors being adapted to respond only to the rays reflected from other locations on said interface in accordance with the density of said fluid at said other locations on said interface, the reflection or refraction of all of said rays impinging on said interface being determined in accordance with Snell's Law and detection means connected to said light sensors for detecting the response of said light sensors to said rays reflected from said interface, said body including said lower portion provided with a plurality of reflective areas and wherein said group of divergent rays from said light-emitting means is directed onto said reflective areas for reflection thereby onto said interface within said body, said rays reflected from some of said reflective areas impinging internally on said interface at first spaed-apart locations for reflection from said interface onto a first group of correspondingly spaced light sensors for indicating the absence of fluid at said first spaced-apart locations, said rays reflected from other of said reflective areas impinging internally on said interface at second spaced-apart locations for reflection onto a second group of correspondingly spaced light sensors for indicating both the presence of water and the fuel index of refraction and therefore the density of the fuel at said second spaced-apart locations.

Claim 12

A water/density detector for a fuel tank or the like comprising, in combination, an elongated light-transmitting body adapted to be disposed within a fuel tank in an upstanding position with the lower portion of said body adjacent the bottom of said tank, said body having a side face forming an interface with the fluid in said tank, said body having a plurality of internal reflection areas adjacent a marginal edge of said body, light-emitting means on said body for transmitting emitted light in the form of a group of divergent rays within said body onto said interface in a plurality of regularly disposed light emission paths, a plurality of light sensors mounted on said body in optical communication with the light reflection paths of said rays reflected from said interface within said body, some of said sensors being adapted to respond only to rays reflected from said interface for indicating the absence of fluid at spaced apart locations on said interface from which said rays are reflected, other of said sensors being adapted to respond only to the rays reflected from other locations on said interface in accordance with the density of said fluid at said other locations on said interface, the reflection or refraction of all of said rays impinging on said interface being determined in accordance with Snell's Law and detection means connected to said light sensors for detecting the response of said light sensors to said rays reflected from said interface, said body including said lower portion provided with a plurality of reflective areas and wherein said group of divergent rays from said light-emitting means is directed onto said reflective areas for reflection thereby onto said interface within said body, said rays reflected from some of said reflective areas impinging internally on said interface at first spaed-apart locations for reflection from said interface onto a first group of correspondingly spaced light sensors for indicating the absence of fluid at said first spaced-apart locations, said rays reflected from other of said reflective areas impinging internally on said interface at second spaced-apart locations for reflection onto a second group of correspondingly spaced light sensors for indicating both the presence of water and the fuel index of refraction and therefore the density of the fuel at said second spaced-apart locations.

Claim 13

A water/fuel density detector for a fuel tank or the like in accordance with claim 10 wherein said light-emitting means and said plurality of light sensors are positioned on the upper portion of said light-transmitting body.

Claim 14

A water/fuel density detector for a fuel tank or the like in accordance with claim 11 wherein said body marginal edge portion extends oppositely from said interface in an angularly disposed relationship therewith, said marginal edge portion being of saw-toothed configuration for defining said reflective areas.

Claim 15

A water/fuel density detector for a fuel tank or the like in accordance with claim 12 wherein said body is of triangular shape having an apex disposed adjacent the bottom of said fuel tank.

Claim 16

A water/fuel density detector for a fuel tank or the like in accordance with claim 13 wherein said plurality of reflective areas includes a mirror-like surface adjacent said apex for reflecting said another group of said rays onto said second spaced-apart locations and wherein said second spaced-apart locations are positioned on the lower portion of said interface.

Claim 17

A water/fuel density detector for a fuel tank or the like in accordance with claim 14 wherein said reflective areas for reflecting said rays onto said first spaced-apart locations are adapted to impinge said reflective rays on said interface at angles of incidence of between approximately 60° to 75°.

Claim 18

A water/fuel density detector for a fuel tank or the like in accordance with claim 15 wherein said arcuate, mirror-like surface for reflecting said rays onto said second spaced-apart locations are adapted to impinge said reflective rays on said interface at angles of incidence of between approximately 62° to 77° wherein the ray incident at 62° will reflect upon the presence of water at said interface and will refract upon the presence of oil at said interface and wherein rays having angles of incidence of between 68° to 77° will reflect at low fuel indices of refraction and refract at high indices of refraction.