Refractometer gauge

Claim 2

A refractometer for measuring the relative change in the index of refraction of a fluid comprising: a rod having an obtuse angular bend formed intermediate the ends thereof; a source of light, having a wave length to which said rod is transparent, positioned adjacent to one end of said rod; means disposed adjacent to the other end of said rod from said light source for detecting variations of light intensity transmitted through said rod; and means for maintaining the angularly bent portion of said rod immersed in said fluid, whereby the relative change in intensity of light detected by said detecting means is a function of the relative change in refractive index of said fluid.

Claim 3

The refractometer of clAim 1 wherein said obtuse angular bends is approximately 105*.

Claim 4

The refractometer of claims 1 wherein the leg of said rod between said source of light and said obtuse angular bend is longer than the other leg of said rod between said light intensity detecting means and said obtuse angular bend.

Claim 5

The refractometer of claim 1 further including means for temperature compensation of said detecting means for changes in temperature of said fluid whereby the absolute range of relative change in intensity of light detected by said detecting means remains substantially constant for all operating temperatures of said fluid.

Claim 6

The refractometer of claim 3 wherein the temperature compensating means comprises said detecting means comprising a temperature dependent photoresistor and encapsulated in plastic along with said light source and said rod, except for the angularly bent portion which projects from said plastic and is exposed to said fluid when the encapsulated assembly is immersed in said fluid, whereby the encapsulated assembly is maintained at substantially the same temperature as said fluid.

Claim 7

The refractomer of claim 1 further including a means for maintaining the intensity of said light source at a substantially constant level of luminesence.

Claim 8

The refractometer of claim 6 wherein the light source constant intensity maintaining means comprises: an incandescent electric light bulb having a transistor connected in series therewith for providing current thereto, a photoresistor and a resistor combination having the base of said transistor connected to the junction thereof and said combination being connected in parallel with said series connected light bulb and transistor, said photoresistor being illuminated by said light bulb and varying the resistance of said photoresistor, and thereby varying the base potential of said transistor as a function of the intensity of said light bulb whereby the flow of current from said transistor to said light bulb is controlled in a manner so as to maintain the intensity of said light bulb at a substantially constant level.

Claim 9

The refractometer of claim 1 wherein the light intensity detecting means comprises: a photoresistor positioned adjacent to the end of said rod opposite said light source and connected in series with one side of a variable center tapped resistor, a resistor connected in series with the other side of said variable resistor and in parallel with said photoresistor, a current output meter connected on one side at the junction of said photoresistor with the variable resistor and on the other side at the junction of said resistor with the variable resistor, said photoresistor being illuminated by light transmitted through said rod and varying the resistance of said photoresistor, and thereby varying the current flowing to said output meter as a function of the variation in light intensity transmitted through said rod, whereby said output meter records the relative change in intensity of said transmitted light which is a function of the relative change in refractive index of said fluid.

Claim 10

A refractometer for measuring the relative change in the index of refaction of a fluid comprising: a rod having an obtuse angular bend of approximately 105* formed intermediate the ends thereof: one leg of said rod between the obtuse angular bend and one of said ends thereof being longer than the other leg of said rod between the obtuse angular bend and the other of said ends thereof; an incandescent electric light bulb, having a wave length to which said rod is transparent, positioned adjacent to the end of the longer leg of said rod; means for maintaining the intensity of said light bulb at a substantially constant level of luminesence; means disposed adjacent to the other end of said rod opposite said light bulb for detecting variations of light intensity transmitted through said rod, said means including a photoresistor positioneD adjacent to said end of the rod and connected in series with one side of a variable center tapped resistor, and a resistor connected in series with the other side of said variable resistor and in parallel with said photoresistor, and a current output meter connected on one side at the junction of said photoresistor with the variable resistor and on the other side at the junction of said resistor with the variable resistor, said photoresistor being illuminated by light transmitted through said rod and varying the resistance of said photoresistor, and thereby varying the current flowing to said output meter as a function of the variation in light intensity transmitted through said rod; means for temperature compensation of said detecting means including said photoresistor being temperature dependent and being encapsulated in plastic along with said light bulb and the ends of said rod, whereby the encapsulated assembly is maintained at substantially the same temperature as said fluid in which it is immersed and the absolute range of relative change in intensity of light detected by said photoresistor remains substantially constant for all operating temperatures of said fluid; means for maintaining the angularly bent portion of said rod immersed in and exposed to said fluid, whereby the relative change in intensity of light detected by said detecting means is a function of the relative change in refractive index of said fluid.

Claim 11

A refractometer for measuring the relative change in the index of refaction of a fluid comprising: a rod having an obtuse angular bend of approximately 105* formed intermediate the ends thereof: one leg of said rod between the obtuse angular bend and one of said ends thereof being longer than the other leg of said rod between the obtuse angular bend and the other of said ends thereof; an incandescent electric light bulb, having a wave length to which said rod is transparent, positioned adjacent to the end of the longer leg of said rod; means for maintaining the intensity of said light bulb at a substantially constant level of luminesence; means disposed adjacent to the other end of said rod opposite said light bulb for detecting variations of light intensity transmitted through said rod, said means including a photoresistor positioneD adjacent to said end of the rod and connected in series with one side of a variable center tapped resistor, and a resistor connected in series with the other side of said variable resistor and in parallel with said photoresistor, and a current output meter connected on one side at the junction of said photoresistor with the variable resistor and on the other side at the junction of said resistor with the variable resistor, said photoresistor being illuminated by light transmitted through said rod and varying the resistance of said photoresistor, and thereby varying the current flowing to said output meter as a function of the variation in light intensity transmitted through said rod; means for temperature compensation of said detecting means including said photoresistor being temperature dependent and being encapsulated in plastic along with said light bulb and the ends of said rod, whereby the encapsulated assembly is maintained at substantially the same temperature as said fluid in which it is immersed and the absolute range of relative change in intensity of light detected by said photoresistor remains substantially constant for all operating temperatures of said fluid; means for maintaining the angularly bent portion of said rod immersed in and exposed to said fluid, whereby the relative change in intensity of light detected by said detecting means is a function of the relative change in refractive index of said fluid.