Method and apparatus for fluorescent sensing

• US 4,651,010 A
• Filed: 06/04/1984
• Issued: 03/17/1987
• Est. Priority Date: 06/04/1984
• Status: Expired due to Fees

• Current Assignee: Laser Science, Inc. (Thermo Fisher Scientific Incorporated)
• Original Assignee: Laser Science, Inc. (Thermo Fisher Scientific Incorporated)
• Inventors: Javan, Ali
• Primary Examiner(s): Fields, C. E.
• Assistant Examiner(s): Hannaher, Constantine
• Application Number:
  US06/617,165
• Time in Patent Office: 1,016 Days
• Field of Search: 250/458.1, 250/459.1, 250/461.1, 250/338 GA, 250/301, 250/304, 250/253, 436/166, 436/172, 436/104, 422/52
• US Class Current: 250/458.1
• CPC Class Codes: G01N 21/643 non-biological material
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence

Abstract

A sensing system for the detection of trace gases in the atmosphere or contaminates on a surface. Particular chemical substances are detected at remote points by placing a sensor unit in the vicinity of the area to be examined and illuminating the area with a laser beam generated by the sensor unit. An optical detector, also carried by the sensor unit, registers the fluorescence produced by the substance illuminated and relays this information by a telemetry link back to the base site. The utility of the system is broadened by providing a chemical reactant selected to react with the substance to be detected to produce a reaction product that fluoresces strongly at the wavelength of the laser light. The chemical reactant is carried by the sensor unit and is sprayed into the area to be examined. The sensor unit carrying the chemical reactant can also be used on location, for example, with a hand-held unit that sprays the chemical reactant on a surface suspected of being contaminated and detecting the resulting fluorescence of the reaction product.

Claims

1. Apparatus for remote sensing of a chemical substance responsive by fluorescence to laser light illumination comprising

a sensor unit positioned adjacent an area to be examined for the substance including

a laser arranged to illuminate at least a portion of said area to produce fluorescence from any of such substance present in the illuminated portion of said area,

optical detection means responsive to said fluorescence,

a storage chamber,

a chemical reactant carried within said chamber and capable of reacting with a specific agent to produce said chemical substance,

means for spraying said chemical reactant into said area, and

a telemetry transmitter responsive to said optical detection means and arranged to radiate a signal having characteristics dependent upon the presence or absence of said fluorescence,

a telemetry receiver positioned remotely from said sensor unit arranged to receive said signal, and

indicator means coupled to said receiver and responsive to the signal received by said receiver.

2. Apparatus as claimed in claim 1 including

a projectile incorporating said sensor unit, and

launching means positioned remotely from the said area to be examined and capable of launching said projectile.

3. A portable sensor for sensing the presence of a contaminate on a surface by detecting the presence of a predetermined reaction product produced by a chemical reaction between said contaminate and a chemical reagent including

a chamber having therein a supply of said chemical reagent,

spray means for spraying said reagent on said surface thereby to produce said reaction product in the presence of said contaminate,

a laser capable of illuminating said surface and causing fluorescence of said reaction product,

optical detection means responsive to said fluorescence,

indicator means under the control of said optical detection means for indicating the presence of said reaction product and thereby the presence of said contaminate,

battery power supply means arranged to provide power for said laser, and said optical detection means, and

a unitary housing containing said power supply means, said laser, said chamber and said optical detection means.

4. The method of detecting the presence of a chemical substance situated in a remote area comprising the steps of

providing a telemetry receiver,

positioning a sensor unit remotely from said receiver and in the vicinity of the area to be examined for the presence of said substance,

discharging into said area from said sensor unit a chemical reaction agent capable of reacting with said substance to produce a reaction product capable of fluorescing,

illuminating at least a portion of said area with laser light from said sensor unit capable of causing said reaction product to fluoresce,

optically detecting at said sensor unit the presence or absence of fluoresence by said reaction product,

radiating from said detection assembly a telemetry signal responsive to said optical detection, and

receiving said signal at said telemetry receiver.

5. The method as claimed in claim 4 including the steps of

providing launching means positioned remotely from said remote area where said chemical substance is to be detected, and

launching said sensor unit into said remote area.