Mercury analysis system and method

Claim 3

The method according to claim 1 wherein said fluid is a gas and said steps of placing sample and removing sample from said vessel consists in passing said gas through said vessel at a given flow rate for a given time period.

Claim 4

The method according to claim 2 wherein said gas is injected into said vessel at a point near said first end of said vessel so that said gas flows along and adjacent the interior noble-metal-coated surface of said vessel and out said second end of said vessel.

Claim 5

The method according to claim 2 wherein said gas is injected into said vessel through a pipe which extends into said vessel at said second end and opens into said vessel adjacent said first end and said gas is caused to flow through said pipe into said vessel along and adjacent the interior noble-metal-coated surface of said vessel and out said second end of said vessel by applying a vacuum to said second end of said vessel.

Claim 6

The method according to claim 2 wherein said vessel is positioned in a generally upright position while said gas is being passed through said vessel.

Claim 7

The method according to claim 1 wherein said fluid sample is an aqueous solution and said method includes the steps of adding a reducing agent to the given amount of aqueous solution in said vessel; sealing said vessel; and agitating said aqueous solution and reducing agent for a given period of time to facilitate reduction of mercury compounds to free metal mercury and to facilitate adsorption of said mercury by said noble metal coating.

Claim 8

The method according to claim 6 wherein said aqueous solution sample includes dissolved solids and said method includes the initial steps of; dissolving a solid in an acid and diluting the acid-dissolved solid with water to form the aqueous solution sample.

Claim 9

The method according to claim 7 wherein said solid is a foodstuff.

Claim 10

The method according to claim 6 wherein said step of agitating said solution consists essentially in shaking said vessel.

Claim 11

The method according to claim 6 wherein said aqueous solution is agitated for at least five minutes.

Claim 12

The method according to claim 6 including the steps of rinsing and drying said vessel prior to heating said vessel.

Claim 13

The method according to claim 6 wherein said sample consists essentially of approximately ten cubic centimeters of water and said reducing agent consists essentially of approximately two cubic centimeters of an approximately 1.5 percent hydroxylamine hydrochloride aqueous solution.

Claim 14

The method according to claim 1 wherein said fluid sample is a gas sample including vapors from a thermally decomposed solid and said method includes the initial step of thermally decomposing a solid to obtain vapors which form said fluid sample.

Claim 15

The method according to claim 1 wherein said noble metal is gold.

Claim 16

The method according to claim 1 wherein said vessel is heated to a temperature between 400*C and 1,300*C.

Claim 17

The method according to claim 1 wherein said vessel is heated by infra-red radiation.

Claim 18

The method according to claim 2 including the initial step of filtering said gas to remove undesirable particles therefrom.

Claim 19

The method according to claim 1 wherein Said ultraviolet light is diffused before being passed endwise through said vessel.

Claim 20

The method according to claim 1 including the step of preheating said fluid sample to vaporize mercury in any solid particles carried in said sample.

Claim 21

The method according to claim 1 including the steps of amplifying and logarithmically converting the light measurements to signal values which are directly related to the concentration of mercury in said fluid sample.

Claim 22

The method according to claim 20 including the steps of subtracting said first signal value from said second signal value; multiplying the difference by a predetermined multiplicand to obtain a numerical value in parts per billion; and printing said numerical value.

Claim 23

The method according to claim 1 including the steps of: passing through said mercury vapor laden air ultraviolet light of a second wavelength band which is near to, but which does not include, said mercury absorption band; measuring the amount of said light having said second wave length which is transmitted through said mercury vapor laden air to obtain a light transmission measurement; passing said light having said second wave length band through said mercury-free air; measuring the amount of said light having said second wave length band which is transmitted through said mercury-free air to obtain a light transmission measurement; amplifying and logarithmically converting said light transmission measurements to signal values proportional to the logarithm of said light transmission measurements; subtracting said first signal value derived from the measurement of transmission through said mercury vapor laden air of ultraviolet light of a wavelength band which is absorbed by mercury vapor, from said signal derived from the measurement of transmission through said mercury vapor laden air of ultraviolet light of said second wave length band to obtain a first difference signal; subtracting said signal value derived from the measurement of transmission through said mercury-free air of ultraviolet light of said wave length band which is absorbed by mercury vapor from said signal derived from the measurement of transmission through said mercury-free air of ultraviolet light of said second wave length band to obtain a second difference signal; and subtracting said second difference signal from said first difference signal to obtain a signal value which is related to the concentration of mercury in said fluid sample and which has had subtracted therefrom the undesired effects of ultraviolet light absorption by other vapors which may be in said vessel in addition to mercury vapor.

Claim 24

The method according to claim 22 including the steps of multiplying said last signal value by a given multiplicand to obtain a numerical value in parts per billion; and printing said numerical value.

Claim 25

A mercury analysis system including a vessel having a noble metal coating on an interior side surface thereof and being supported in a generally upright position with an upper end of the vessel above a lower end and with the lower end of the vessel vented, means for vaporizing mercury stored in said noble metal coating, and means for analyzing the mercury vapor, said analyzing means including a source of ultraviolet light of a wave length band which is absorbed by mercury vapor, said source of ultraviolet light being positioned to pass ultraviolet light endwise through the vessel, means for detecting the amount of light transmitted through the vessel, and means for flushing mercury vapor laden air from the vessel.

Claim 26

A mercury analysis system including a vessel having a noble metal coating on an interior side surface thereof and being supported in a generally upright position with an upper end of the vessel above a lower end and with the lower end of the vessel vented, means for vaporizing mercury stored in said noble metal coating, and means for analyzing the mercury vapor, said analyzing means including a source of ultraviolet light of a wave length band which is absorbed by mercury vapor, said source of ultraviolet light being positioned to pass ultraviolet light endwise through the vessel, means for detecting the amount of light transmitted through the vessel, and means for flushing mercury vapor laden air from the vessel.

Claim 27

The system according to claim 24 including an electronic circuit connected to said detecting means, said electronic circuit including means for amplifying signals generated by light detected by said detecting means and for logarithmically converting the generated signals to signal values related to the concentration of mercury in the mercury vapor laden air, means for memorizing a first generated signal related to the light transmitted throUgh mercury-laden-vapor, means for memorizing a second generated signal related to the light transmitted through mercury-free air, and means for subtracting the first signal from the second signal to obtain difference signal directly related to the concentration of mercury in the mercury vapor laden air.

Claim 28

The system according to claim 25 including means for printing the mercury analysis measurement in parts per billion and wherein said electronic circuit includes a multiplying means connected between said subtracting means and said printing means for multiplying the difference signal by a predetermined multiplicand.

Claim 29

The system according to claim 25 including a second source of ultraviolet light of a wavelength band which is near, but which does not include, the mercury vapor absorption band, said second source being positioned to pass ultraviolet light endwise through the vessel at predetermined times, and wherein a memorizing means is operable to memorize a generated signal obtained when ultraviolet light from said second source is passed through the mercury vapor laden air in the vessel; a memory means is operable to memorize a generated signal obtained when ultraviolet light from said second source is passed through mercury-free air in the vessel, said subtracting means being operable to subtract said first signal obtained when ultraviolet light from said first source is passed through the mercury vapor laden air in the vessel from said signal obtained when ultraviolet light from said second source is passed through the mercury vapor laden air in the vessel to obtain a first difference signal, memory means operable to memorize a third signal obtained when ultraviolet light from said first source is passed through mercury-free air in the vessel, memory means operable to memorize a fourth signal obtained when ultraviolet light from said second source is passed through mercury-free air in the vessel, said subtracting means being operable to subtract said third signal from said fourth signal to obtain a second difference signal, and said electronic circuit includes a means for memorizing said first difference signal and a means for memorizing said second difference signal and a second subtracting means for subtracting said second difference signal from said first difference signal to obtain a third difference signal which is directly related to mercury vapor vaporized in the test tube and which has had subtracted therefrom the undesired effects of ultraviolet light absorption by other vapors which may be in the vessel in addition to mercury vapor.

Claim 30

The system according to claim 27 including means for printing the mercury analysis of a fluid sample in parts per billion and wherein said electronic circuit includes multiplying means connected between said second subtracting means and said printing means for multiplying said third difference signal by a predetermined multiplicand to obtain a numerical value in parts per billion of the mercury concentration in the fluid sample.

Claim 31

The system according to claim 24 wherein said flushing means includes a filter for removing mercury vapors from air used as a flushing medium, and a flush nozzle having its outlet orifice arranged to inject flushing air into the lower end of the vessel adjacent one side of the vessel and in a direction generally parallel to the longitudinal axis of the vessel.

Claim 32

The system according to claim 24 including an ultraviolet band pass filter situated between one end of the vessel and said detecting means.

Claim 33

The system according to claim 24 wherein said vaporizing means is an infra-red heater.

Claim 34

The system according to claim 24 wherein said light source is horizontally spaced from the upper end of the vessel and a prism is situated above the upper end of the vessel for reflecting light from said light source downwardly through vessel.

Claim 35

The system according to claim 24 including means interposed between said light source and the vessel for diffusing the light frOm said light source.