US5221871A — Surface wave gas sensor

Claim 1

Independent Claim 133 words

A gas sensor which is essentially composed of a surface wave delay line which determines the frequency of an oscillating circuit, where a less than 0.1 μm thick organic, non-conducting solid film is located on the delay line to adsorb the gas to be determined, wherein the delay line is completely coated with the solid film, the delay line has a resonance frequency in the range from 0.5 To 2. GHz includes transformers at each end to define a surface wave transformer length, the delay line has dimensions such that the surface wave transformer length is greater than the length of the delay line and the transformers are designed so that the response curve in the response spectrum of the delay line does not permit mode discontinuities, corresponding to a small band width.

Claim 2

Dependent Claim 133 words

A gas sensor which is essentially composed of a surface wave delay line which determines the frequency of an oscillating circuit, where a less than 0.1 μm thick organic, non-conducting solid film is located on the delay line to adsorb the gas to be determined, wherein the delay line is completely coated with the solid film, the delay line has a resonance frequency in the range from 0.5 To 2. GHz includes transformers at each end to define a surface wave transformer length, the delay line has dimensions such that the surface wave transformer length is greater than the length of the delay line and the transformers are designed so that the response curve in the response spectrum of the delay line does not permit mode discontinuities, corresponding to a small band width.

Claim 3

Dependent Claim 33 words

The invention of claim 1, wherein an angle between the direction of propagation of the surface wave and a cut edge of a substrate receiving said delay lines differ from 90° to 115°.

Claim 4

Dependent Claim 20 words

The invention of claim 2, wherein said substrate comprises quartz and said organic, non-conducting solid film comprises an organic semiconductors.

Claim 5

Dependent Claim 12 words

The invention of claim 3, wherein said organic semiconductors comprise phthalocyanine complexes.

Claim 6

Dependent Claim 21 words

The invention of claim 1, wherein said coating of organic, non-conducting solid film is defined to be a few molecular diameters.

Claim 7

Dependent Claim 138 words

A gas sensor which is essentially composed of a surface wave of at least two delay lines which determine the frequency of an oscillating circuit, where a less than 0.1 μm thick organic, non-conducting solid film is located on the delay lines to adsorb the gas to be determined, wherein the delay lines are completely coated with the solid film, the delay lines having a resonance frequency in the range from 0.5 To 2. GHz and includes transformers at each end to define a surface wave transformer length, the delay lines having dimensions such that the surface wave transformer length is greater than the length of the delay lines and the transformers are designed so that the response curve in the response spectrum of the delay lines do not permit mode discontinuities, corresponding to a small band width.

Claim 8

Dependent Claim 138 words

A gas sensor which is essentially composed of a surface wave of at least two delay lines which determine the frequency of an oscillating circuit, where a less than 0.1 μm thick organic, non-conducting solid film is located on the delay lines to adsorb the gas to be determined, wherein the delay lines are completely coated with the solid film, the delay lines having a resonance frequency in the range from 0.5 To 2. GHz and includes transformers at each end to define a surface wave transformer length, the delay lines having dimensions such that the surface wave transformer length is greater than the length of the delay lines and the transformers are designed so that the response curve in the response spectrum of the delay lines do not permit mode discontinuities, corresponding to a small band width.

Claim 9

Dependent Claim 26 words

The invention of claim 6, wherein one of said delay lines has said organic, non-conducting solid film of a different thickness than the other delay line.

Claim 10

Dependent Claim 33 words

The invention of claim 7, wherein an angle between the direction of propagation of the surface wave and a cut edge of a substrate receiving said delay lines differ from 90° to 115°.

Claim 11

Dependent Claim 19 words

The invention of claim 7, wherein said substrate comprises quartz and said organic, non-conducting solid films comprise organic semiconductors.

Claim 12

Dependent Claim 12 words

The invention of claim 9, wherein said organic semiconductors comprise phthalocyanine complexes.

Claim 13

Dependent Claim 19 words

The invention of claim 6, wherein said coatings of solid films are defined to be a few molecular diameters.

Claim 14

Dependent Claim 26 words

The invention of claim 6, wherein one of said delay lines has said organic, non-conducting solid film of a different film than the other delay line.

Claim 15

Independent Claim 128 words

A method of providing a surface wave gas sensor comprising the steps of: a) providing for a surface wave delay line placed upon a substrate to determine the frequency of an oscillating circuit; said delay line having a resonance frequency in range of from 0.5 to 2. GHz and includes transformer at each end to define a surface wave transformer length, the delay line having dimensions such that the surface wave transformer length is greater than the length of the delay line; b) completely coating a less than 0.1 μm thick organic nonconducting solid film over said delay line; and c) designing the transformers so that the response curve in the response spectrum of the delay line does not permit mode discontinuities, corresponding to a small band width.

Claim 16

Independent Claim 128 words

A method of providing a surface wave gas sensor comprising the steps of: a) providing for a surface wave delay line placed upon a substrate to determine the frequency of an oscillating circuit; said delay line having a resonance frequency in range of from 0.5 to 2. GHz and includes transformer at each end to define a surface wave transformer length, the delay line having dimensions such that the surface wave transformer length is greater than the length of the delay line; b) completely coating a less than 0.1 μm thick organic nonconducting solid film over said delay line; and c) designing the transformers so that the response curve in the response spectrum of the delay line does not permit mode discontinuities, corresponding to a small band width.

Claim 17

Dependent Claim 18 words

The invention of claim 13, additionally including coating said organic, nonconducting solid film by use of Langmuir-Blodgett techniques.

Claim 18

Dependent Claim 19 words

The invention of claim 13, wherein the substrate comprises quartz and the organic, non-conducting solid film comprise organic semiconductors.

Claim 19

Dependent Claim 12 words

The invention of claim 13, wherein said organic semiconductors comprise phthalocyanine complexes.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-06-21	1996-12-21	1997-06-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-06-21	2000-12-21	2001-06-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-06-21	2004-12-21	2005-06-22	$7700.00	Window Closed / Lapsed

Surface wave gas sensor

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