Multi-frequency photo-acoustic detector
First Claim
1. A process for detecting a single specific gas or solid in a mixture or a number of specific mixed gases or solid materials comprising:
- passing said material to be detected into a sample chamber;
modulating multiple beams of electromagnetic radiation having wavelengths corresponding to a characteristic absorbed wavelength of at least one of the chemicals in said material to be detected;
simultaneously passing multiple beams of said modulated electromagnetic radiation incident on said material to be detected in said sample chamber causing multiple acoustical signals at specific frequencies upon absorption of said modulated beams of electromagnetic radiation; and
detecting the acoustical signal corresponding to at least one beat tone or at least one combination tone characteristic of said specific material to be detected.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus and process for detecting a single specific chemical solid or gas in the presence of other chemical solids or gases or for detecting a number of specific mixed chemical solids or gases. The apparatus and process passes multiple beams of electromagnetic radiation incident on the material in a sample chamber producing acoustic signals at specific frequencies when light of specific wavelengths is absorbed. The electromagnetic radiation is selected to have wavelengths corresponding to optical absorption features of at least one specific chemical in the sample chamber. The acoustic signals are detected by at least one beat tone or combination tone characteristic of and representative of the degree of absorption by a specific chemical or multiple specific chemicals desired to be detected. The apparatus and process are especially useful in leak detection in natural gas systems and for detection of pollutants, explosive gases and the like.
-
Citations
25 Claims
-
1. A process for detecting a single specific gas or solid in a mixture or a number of specific mixed gases or solid materials comprising:
-
passing said material to be detected into a sample chamber; modulating multiple beams of electromagnetic radiation having wavelengths corresponding to a characteristic absorbed wavelength of at least one of the chemicals in said material to be detected; simultaneously passing multiple beams of said modulated electromagnetic radiation incident on said material to be detected in said sample chamber causing multiple acoustical signals at specific frequencies upon absorption of said modulated beams of electromagnetic radiation; and detecting the acoustical signal corresponding to at least one beat tone or at least one combination tone characteristic of said specific material to be detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. An apparatus for detecting a single specific gas or solid material in a mixture or a number of specific mixed gases or solid materials comprising:
-
means defining a sample chamber for containing said material; means for generating at least one beam of electromagnetic radiation; means for simultaneously passing incident on said material in said sample chamber multiple beams of modulated electromagnetic radiation at wavelengths corresponding to a characteristic absorbed wavelength of at least one of the chemicals in said material to be detected; means for acoustical detection of multiple acoustical signals at specific frequencies upon absorption of said modulated beams of electromagnetic radiation providing an output electrical signal corresponding to a beat tone or a combination tone characteristic of said specific material or said number of specific mixed materials; and means for detection and indication of said output electrical signal. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
-
Specification