×

Detection of nitrogen containing and nitrogen free explosives

  • US 10,641,752 B2
  • Filed: 05/30/2017
  • Issued: 05/05/2020
  • Est. Priority Date: 05/30/2017
  • Status: Active Grant
First Claim
Patent Images

1. A system for screening for the presence of nitrogen containing explosives, the system comprising:

  • a. a chamber for collecting explosive residues;

    b. a desorber;

    c. a pyrolysis tube for pyrolyzing said explosive residue to generate a gaseous sample from decomposition of the explosive residues comprising NO2;

    d. a pump for pumping the gaseous sample sequentially into a luminol reaction cell followed by transferring a smaller portion of the gaseous sample to a metal oxide sensor (MOS) array or pumping the gaseous sample partially into a luminol cell and partially to an MOS array;

    e. said luminol producing chemiluminescence by a chemical reaction between said luminol and said gaseous sample within said reaction cell;

    f. measuring means comprising photomultiplier tube or photodiode array for measuring the intensity of chemiluminescence and for outputting a first electrical signal indicative of the amount of explosive detected;

    g. a reduced quantity of said gaseous sample configured to be pumped to said metal oxide sensor array to prevent saturation of metal oxide detector;

    h. the MOS array comprising a conductivity sensor having a thin ceramic or fused silica sheet with an oxide sensing layer or oxide film and electrodes for measuring electrical resistance of the oxide sensing layer or oxide film, said electrical resistance being changed by adsorption of said pumped gaseous sample indicating the presence of said explosive;

    whereby the chemiluminescence measurement is refined by the metal oxide sensor measurement to eliminate the interference composition from detection.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×