Patents Assigned to Graphic Controls Canada Ltd.
  • Ethylene oxide monitoring device
    Patent number: 4826772
    Abstract: Monitoring exposure to ethylene oxide using a dosimeter or monitoring device avoids using devices that collect a sample for future testing or devices that must be sent away for lab analysis. The device comprises a reactive coating including a layer of activated alumina particles coated with p-nitrobenzyl pyridine and ammonium chloride, and is adapted to instantly produce a color intensity change directly related to the dosage of the reactive coating to ethylene oxide upon the addition of a developer.
    Type: Grant
    Filed: April 1, 1987
    Date of Patent: May 2, 1989
    Assignee: Graphic Controls Canada, Ltd.
    Inventor: William G. Meathrel
  • Device to indicate the concentration of ethylene oxide in the workplace
    Patent number: 4597942
    Abstract: A visual indicator device and dosimeter in which a liquid crystal composition deposited on an opaque dark-colored carrier substrate undergoes color changes which depend on the concentration, and total quantity, of ethylene oxide to which the device has been exposed. The device serves both to monitor the concentration of ethylene oxide in the environment and to indicate a time-weighted average exposure.
    Type: Grant
    Filed: August 15, 1983
    Date of Patent: July 1, 1986
    Assignee: Graphic Controls Canada Ltd.
    Inventor: William G. Meathrel