A highly sensitive and selective sensor for the detection of halogenated compounds comprises a bead of sodium lanthanum fluoride silicate,... Show moreA highly sensitive and selective sensor for the detection of halogenated compounds comprises a bead of sodium lanthanum fluoride silicate, having the molecular formula NaLa.sub.4 (SiO.sub.4).sub.3 F, in which are embedded two noble metal electrodes, preferably a straight platinum wire near the center and a helical platinum wire near the periphery of the bead. A current passing through the helical wire maintains the sensor temperature at about 550.degree. C. by resistive heating. The electrical resistance between the two wires is deduced from measurements of the current passing through a fixed external resistor when a substantially constant voltage, preferably about 4 volts, is applied between the wires. A decrease in the measured resistance is an indication of the presence of a halogenated compound in the sample of air to which the bead is exposed. The sensor is preferably controlled by a microprocessor or microcomputer that also performs data processing. This system not only detects a halogenated compound of interest, but also measures its concentration. Sponsorship: Illinois Institute of Technology United States Patent Show less
A biosensor comprising a substrate material, at least one antibody covalently immobilized on the substrate material, and a pair of metal... Show moreA biosensor comprising a substrate material, at least one antibody covalently immobilized on the substrate material, and a pair of metal contact electrodes for measuring the impedance of the biosensor. A process for producing a biosensor in accordance with this invention as well as a process for utilizing the biosensor are also disclosed. Sponsorship: Illinois Institute of Technology Sponsorship: United States of America United States Patent Show less
A monitoring system for chemical shipments having an apparatus for detection of a leak from a shipment vessel having a shroud. A first... Show moreA monitoring system for chemical shipments having an apparatus for detection of a leak from a shipment vessel having a shroud. A first chemical sensor is in communication with a chamber of the shroud for detecting the presence of a substance leaking from the vessel. A second sensor is in communication with the ambient environment surrounding the shroud. A monitoring circuit in communication with the first chemical sensor and the second chemical sensor monitors a first chemical sensor output and a second chemical sensor output and signals an information unit dependant on the increase of at least one of the first and second chemical sensors. The information unit emits a signal to an alarm or output device in response to an increase of the magnitude and/or rate of increase of at least one of the first chemical sensor output and the second chemical sensor output. A physical sensor can be in combination with the monitoring circuit. The information unit can be a remote information unit to which the monitoring circuit signals by wireless communication means. Sponsorship: Illinois Institute of Technology United States Patent Show less
