US5420432A — Organic pollutant monitor

Claim 1

Independent Claim 110 words

A method of determining the amount of organic matter in a liquid sample comprising the steps of: (a) passing light of a wavelength in the UV region through the sample and sensing the emergent UV light intensity; (b) making a measurement to provide an indication of the absorption by the sample of visible light; (c) making a further measurement to provide an indication of the amount of scatter of light caused by the sample; and, (d) determining the amount of organic matter in the sample from the measured reduction in UV light intensity by a calculation in which the results from steps (b) and (c) are used for compensation purposes.

Claim 2

Independent Claim 110 words

A method of determining the amount of organic matter in a liquid sample comprising the steps of: (a) passing light of a wavelength in the UV region through the sample and sensing the emergent UV light intensity; (b) making a measurement to provide an indication of the absorption by the sample of visible light; (c) making a further measurement to provide an indication of the amount of scatter of light caused by the sample; and, (d) determining the amount of organic matter in the sample from the measured reduction in UV light intensity by a calculation in which the results from steps (b) and (c) are used for compensation purposes.

Claim 3

Dependent Claim 19 words

A method as claimed in claim 1, wherein UV light of 254 nm wavelength is used in step (a).

Claim 4

Dependent Claim 27 words

A method as claimed in claim 1, wherein the visible light is selected to be of one or more wavelengths that are highly absorbed by the sample.

Claim 5

Dependent Claim 18 words

A method as claimed in claim 1, wherein the visible light is selected to be of yellow wavelength.

Claim 6

Dependent Claim 28 words

A method as claimed in claim 1, wherein step (c) comprises passing light through the liquid sample and measuring the amount of light scattered at a particular angle.

Claim 7

Dependent Claim 23 words

A method as claimed in claim 1, wherein steps (a), (b) and (c) are carried out on the sample under the same conditions.

Claim 8

Dependent Claim 39 words

A method as claimed in claim 6, including an additional step of measuring one or more additional variable(s) and wherein the additional step is carried out on the sample under the same conditions as steps (a), (b) and (c).

Claim 9

Dependent Claim 20 words

A method as claimed in claim 1, wherein the liquid sample is filtered prior to steps (a), (b) and (c).

Claim 10

Dependent Claim 20 words

A method as claimed in claim 8, wherein the filtering does not remove particles of less than about 1 mm.

Claim 11

Dependent Claim 18 words

A method as claimed in claim 1, including an additional step of measuring one or more additional variable(s).

Claim 12

Dependent Claim 16 words

A method as claimed in claim 10, wherein the additional variable is measured for compensation purposes.

Claim 13

Dependent Claim 23 words

A method as claimed in claim 10, wherein an additional variable is the emergent light intensity of UV light of a second wavelength.

Claim 14

Dependent Claim 19 words

A method as claimed in claim 12, wherein the second wavelength corresponds to a characteristic absorption wavelength of ammonia.

Claim 15

Dependent Claim 17 words

A method as claimed in claim 10, wherein an additional variable is the temperature of the liquid.

Claim 16

Dependent Claim 17 words

A method as claimed in claim 10, wherein an additional variable is the pH of the liquid.

Claim 17

Dependent Claim 20 words

A method as claimed in any one of claim 10, wherein an additional variable is the conductivity of the liquid.

Claim 18

Dependent Claim 16 words

A method as claimed in claim 10, wherein the BOD of the liquid sample is determined.

Claim 19

Dependent Claim 89 words

Apparatus for determining the amount of organic matter in a liquid sample, the apparatus comprising first means for passing light of a wavelength in the UV region through the liquid sample and sensing the emergent UV light intensity, second means for making a measurement to provide an indication of the absorption by the sample of visible light, and third means for making a further measurement to provide an indication of the amount of scatter if light caused by the sample including means for measuring one or more additional variables.

Claim 20

Dependent Claim 89 words

Apparatus for determining the amount of organic matter in a liquid sample, the apparatus comprising first means for passing light of a wavelength in the UV region through the liquid sample and sensing the emergent UV light intensity, second means for making a measurement to provide an indication of the absorption by the sample of visible light, and third means for making a further measurement to provide an indication of the amount of scatter if light caused by the sample including means for measuring one or more additional variables.

Claim 21

Dependent Claim 80 words

Apparatus for determining the amount of organic matter in a liquid sample, the apparatus comprising first means for passing light of a wavelength in the UV region through the liquid sample and sensing the emergent UV light intensity, second means for making a measurement to provide an indication of the absorption by the sample of visible light, and third means for making a further measurement to provide an indication of the amount of scatter of light caused by the sample.

Claim 22

Dependent Claim 80 words

Apparatus for determining the amount of organic matter in a liquid sample, the apparatus comprising first means for passing light of a wavelength in the UV region through the liquid sample and sensing the emergent UV light intensity, second means for making a measurement to provide an indication of the absorption by the sample of visible light, and third means for making a further measurement to provide an indication of the amount of scatter of light caused by the sample.

Claim 23

Dependent Claim 37 words

Apparatus as claimed in claim 19, including processing means for determining the amount of organic matter in the sample from an output of the first means, adjusted in accordance with outputs from the second and third means.

Claim 24

Dependent Claim 18 words

Apparatus as claimed in claim 20, wherein the processing means uses the measured additional variable for compensation purposes.

Claim 25

Dependent Claim 19 words

Apparatus as claimed in claim 20 wherein the processing means are adapted to calculate the BOD of the sample.

Claim 26

Dependent Claim 18 words

Apparatus as claimed in claim 19, wherein the apparatus is contained in a single housing and/or is portable.

Claim 27

Dependent Claim 20 words

Apparatus as claimed in claim 19, wherein the first, second and third means are provided in a single measuring cell.

Claim 28

Dependent Claim 25 words

Apparatus as claimed in claim 19, wherein the apparatus is not provided with a filter having a pore size of less than about 1 mm.

Claim 29

Dependent Claim 97 words

A monitoring system for use in a method of determining the amount of organic matter in a liquid source, which system comprises apparatus as claimed in claim 19 in combination with sampling apparatus for withdrawing a sample from a liquid source having an open surface, which sampling apparatus comprises a buoyant sampling head provided with an inlet port that communicates with a duct for connection to suction means, the sampling apparatus being so arranged that, in use, the sampling head floats on the surface of the liquid source and the inlet port is disposed beneath that surface.

Claim 30

Dependent Claim 17 words

A monitoring system as claimed in claim 26, wherein a filter is disposed across the inlet port.

Claim 31

Dependent Claim 26 words

A monitoring system as claimed in claim 27, wherein the surface area of the filter is substantially larger than the average cross-sectional area of the duct.

Claim 32

Dependent Claim 25 words

The use of a monitoring system as claimed in claim 26 in a method of determining the amount of organic matter in a liquid source.

Claim 33

Dependent Claim 22 words

The use as claimed in claim 29 of a monitoring system, wherein the system is used on a long-term and/or continuous basis.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-05-29	1998-11-28	1999-05-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-05-29	2002-11-28	2003-05-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-05-29	2006-11-28	2007-05-30	$7700.00	Window Closed / Lapsed

Organic pollutant monitor

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