×

Excitation and detection apparatus for remote sensor connected by optical fiber

  • US 4,900,933 A
  • Filed: 03/20/1987
  • Issued: 02/13/1990
  • Est. Priority Date: 09/08/1986
  • Status: Expired due to Fees
First Claim
Patent Images

1. Sensing apparatus comprising:

  • an optical fiber;

    a phosphorescent material coupled to one end of said optical fiber, said phosphorescent material emitting a long-live luminescence when exposed to energy in a predetermined wavelength range, said long-lived luminescence including a measuring wavelength having an intensity responsive to a quantity being sensed and a reference wavelength having a substantially constant intensity as a function of the quantity being sensed;

    source means coupled to the other end of said optical fiber for generating an incident pulsed energy signal within said predetermined wavelength range to cause said phosphorescent material to generate said long-lived luminescence; and

    detector means coupled to the other end of said optical fiber for selectively detecting the long-lived luminescence from said phosphorescent material when said incident pulsed energy signal has substantially ceased and any short-lived background luminescence generated in the apparatus has substantially ceased, said long-lived luminescence having a longer duration than said incident pulsed energy signal and said short-lived luminescence, said detector means includinga first detector channel for detecting the measuring wavelength and providing a first signal representative of the intensity of the measuring wavelength,a second detector channel for detecting the reference wavelength and providing a second signal representative of the intensity of the reference wavelength,signal processing means responsive to the relative values of said first signal and said second signal for providing an output representative of the quantity being sensed, andspurious signal detecting means for determining that said detector means is receiving spurious light signals on said optical fiber.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×