Westinghouse Electric Corporation

The United States of America As Represented by the Secretary of

Frederick M Ryan

Robert C Miller

Robert L Nelson

Donald W Feldman

Milton S Gottlieb

Gerald L Carlson

Frank M Vodoklys

Paul C Handke

An improved system for quantitative chemical analysis incorporates a chromatographic column. A radiation source of a predetermined range of wavelengths is in optical communication with an emerging specie from the chromatographic column by of a first optical path whereby radiation is modified by characteristic of the specie. A detector is in optical communication with the emerging specie by a second optical path whereby a first output signal reflective of the detected radiation is generated. An acousto-optic tunable filter system is disposed in one of either the first or second optical paths. The radiation is passed through the crystal at a predetermined angle relative to the crystal's optic axis. An acoustic transducer is coupled to the crystal to launch acoustic waves into the crystal to interact with a selected narrow bandwidth portion of the radiation to make it distinguishable from the remaining radiation. A computer to which the detector output signal is applied determines the emerging specie by the identifiable characteristics. An auxiliary detector responsive to the emerging specie can be associated with the chromatographic column. A parallel optical path can also be included to define a reference cell. A second output signal reflective of the detected radiation passing through the parallel optical path is generated. The difference between the first and second output signals represents a measure of the emerging specie's absorption characteristic. In an alternative embodiment, an acoustooptic dispersive light filter can be inserted in the system.

System for chemical analysis

An acousto-optic tunable filter configuration and a method for the operation thereof, whereby the tuning range is extended. A non-collinear acousto-optic tunable filter crystal has a first transducer bonded to one transducer face of the crystal and a single transducer bonded on the opposite crystal face which crystal face is cut so as to be parallel to the first transducer. The first transducer operates at a center frequency f.sub.1 and the second transducer operates at a center frequency f.sub.2. By launching acoustic waves having a center frequency f.sub.1 into the crystal from the crystal's first side acoustic waves propagate in a first direction such that the interaction of the acoustic wave with the light results in the absorption of a phonon. Acoustic waves having a center frequency f.sub.2 are launched into the crystal from the crystal's second side and propagate in a second direction which is anti-parallel to the first direction such that the interaction with the light by the second series of acoustic waves results in the stimulated emission of a phonon.

Acousto-optic tunable filter with two acoustic channels

The improved system for remote chemical analysis of this invention includes a quartz halogen bulb as a source of infrared light, quartz fibers leading to and from a sample cell, a non-collinear thallium arsenic selenide, AOTF to perform spectral analysis and a lead selenide detector, Both the AOTF and the detector are interfaced with a microcomputer. Under the control of the microcomputer, this equipment gathers and interprets transmission spectra obtained through the passage of infrared light through the sample cell. Microcomputer interface provides rapid random-access to the RF frequency driving the AOTF, which selects the wavelength of light to be examined and also provides routines for sample averaging and the comparison of various reference spectra. An acousto-optic device mounted in an enclosure which includes input and output crystal fiber connectors is also provided.

System for remote chemical analysis

An improved automated acousto-optic analyzer system includes an acousto-optic tunable filter which is coupled with a source of radiation to produce pulsed light at predetermined wavelengths. This light is transmitted through a gas stack containing gases to be analyzed, to a distant detector. The configuration of the acousto-optic tunable filter, radiation source on one side of an environment of interest and a detector on the opposite side of an environment of interest produces spatial separation of the tuned, diffracted light from the undiffracted broad spectrum of the light source at the detector. This configuration eliminates the need for polarizers in the system. It also combines the tuning function of the AOTF with a chopping function, allowing extraneous radiation to be discriminated against. Thus the improved configuration of the disclosed invention permits effective operation of the gas analysis system in a gas stack characterized by extremely high ambient temperatures.

Automated acousto-optic infra-red analyzer system for monitoring stack

The invention provides an apparatus for the detection of a selected species in a gas sample and includes a photo-acoustic detector coupled to an infrared radiation source with an acousto-optic tunable filter disposed between the source of infrared radiation and photo-acoustic detector. This combination is capable of measuring concentrations of controlled vapors in the parts-per-million range. These measurements may be performed in a few seconds via the portable gas detection and measurement device of this invention.

Method and apparatus for the detection and measurement of gases

A temperature detection apparatus is provided which comprises at least one light source, light guide and light detector. The light guide is placed in thermal communication with target areas whose temperatures are of interest, particularly for application in electromechanical apparatus where the target area whose temperature is of interest is relatively inaccessible and/or an electrical temperature probe would encounter interference. The light guide itself indicates temperature changes since it only transmits light when the temperature-dependent refractive index of its core exceeds that of its cladding.

Temperature detection using the refractive indices of light guides

Small particles for tagging of objects to be identified comprise luminescent material plus other material which provides information indicia for tagging purposes. Included in the tagging particles are very small particles of magnetic material which is reflective both for the radiations which excite the luminescent material and also for the radiations generated by the excited luminescent material. The inclusion of the reflective magnetic particles introduces only a minimal decrease in the effectiveness of the luminescent material to provide a spotting or locating function. The particles may thus be located either by their luminescent response, or by magnetic pickup, or both. Inorganic species of these particles are especially useful for tagging explosives for post-explosion indentification of the explosives.

Tagging particles which are easily detected by luminescent response, or

Phosphor-explosive material combination and method wherein a small amount of inorganic phosphor is mixed with explosive material to provide an indicia or label of information regarding the explosive, either before or after detonation of same. The phosphor can readily be located with an ultraviolet lamp even after the explosive has been detonated, and by correlating the phosphor emission spectra with data known about the explosive when it is manufactured, the explosive can be identified. Line-emitting phosphors are especially useful because of their distinctive emision characteristics, which provide a vast number of possible combinations of emissions which are correlated against the data known about the explosive when it is manufactured. Preferably the phosphor is formed as a combination of finely divided 'spotter' phosphor and finely divided 'coding' material held together by a binder in the form of small conglomerates, in order to facilitate initial location and later identification of same. There exists a vast number of different combinations of distinctive fluorescent emissions, and these can be combined to label any item for later identification.

Phosphor combination, particularly adapted for use with explosives, for

Phosphor-explosive material combination and method wherein a small amount of inorganic phosphor is mixed with explosive material to provide an indicia or label of information regarding the explosive, either before or after detonation of same. The phosphor can readily be located with an ultraviolet lamp even after the explosive has been detonated, and by correlating the phosphor emission spectra with data known about the explosive when it is manufactured, the explosive can be identified. Line-emitting phosphors are especially useful because of their distinctive emission characteristics, which provide a vast number of possible combinations of emissions which are correlated against the data known about the explosive when it is manufactured. Preferably the phosphor is formed as a combination of finely divided 'spotter' phosphor and finely divided 'coding' material held together by a binder in the form of small conglomerates, in order to facilitate initial location and later identification of same. There exists a vast number of different combinations of distinctive fluorescent emissions, and these can be combined to label any item for later identification.

Phosphor identification method, particularly adapted for use with

A fluorescent lamp fixture, or the lamp for use in such a fixture, has organic phosphor positioned to intercept a predetermined proportion of the radiations passing through the lamp envelope and to convert the intercepted radiations to longer wavelength radiations. The radiations passing the envelope which are not converted plus those radiations which are converted when blended together produce light suitable for illumination.

Low-pressure fluorescent discharge device which utilizes both inorganic

An inorganic fluorescent phosphor consisting of a spotting phosphor and a coding phosphor is employed for tagging purposes, as for example, tagging explosives to provide post detonation information. The spotting phosphor consists of an inorganic fluorescent material which is excited by UV to produce readily detectable band-type emission, but which produces little or no emission at certain excitation wave lengths. The coding phosphor consists of a different inorganic fluorescent material which emits a line-type emission and which fluoresces efficiently at those excitation wave lengths at which the spotting phosphor produces little or no emission. Exemplary spotting phosphors are zinc silicate and calcium silicate activated by manganese, which show no excitation at a UV radiation of 325 nm. Suitable coding phosphors are yttrium vanadate activated by trivalent rare earth ions, such as europium, thulium, erbium, dysprosium or Samarium. This combination of spotters and coding phosphors in cemented phosphor grains employed for tagging purposes enables the quantity of expensive coding phosphors required to be drastically reduced.

Growing community of inventors

Loyalhanna, PA, United States of America

Frederick M Ryan