Ultraviolet radiation dosimeter

• US 4,212,535 A
• Filed: 08/29/1978
• Issued: 07/15/1980
• Est. Priority Date: 11/02/1977
• Status: Expired due to Term

• Current Assignee: National Research Council Canada
• Original Assignee: Canadian Patents and Development Limited
• Inventors: Makow, David M., Sanders, Corey L.
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US05/937,800
• Time in Patent Office: 686 Days
• Field of Search: 356/51, 356/215, 250/372
• US Class Current: 356/51
• CPC Class Codes: G01J 1/50 using change in colour of an indicator, e.g. actinometer

Abstract

A method for detecting, monitoring or measuring visible and ultraviolet radiation exposure wherein a liquid crystal element covered with a coating layer transparent to the radiation is placed in the path of the radiation to be monitored and then the shift of the spectral reflectance or transmittance of the element is measured, this shift being a measure of the radiation dosage. This shift may be measured using reference liquid crystal elements or a spectrophotometer or similar measuring devices.

Claims

1. A device for detecting, monitoring and measuring visible and ultraviolet radiation exposures or doses comprising at least one first liquid crystal element mounted on a card or plate for positioning in the path of the radiation to be monitored and at least one second liquid crystal element mounted adjacent the first element, said first element covered with a coating layer transparent to radiation, said second element masked or covered with a coating layer impervious to all or part of the radiation and having been pre-exposed to radiation of the kind being measured to cause a color change, the amount of the radiation pre-exposure having been determined and being a measure of the amount of radiation the first liquid crystal element receives when a color change occurs which brings the two colors into a color match condition.

2. A device for detecting, monitoring or measuring visible and ultraviolet radiation exposure or doses comprising at least one first liquid crystal element mounted on a card or plate for positioning in the path of the radiation to be monitored and at least one second liquid crystal element mounted adjacent the first element, said first element covered with a coating layer transparent to radiation, said second element masked or covered with a coating layer impervious to all or part of the radiation such that a noticeable color change of the first element as compared to the second indicates an amount of radiation having been received.