Patent ID: 7132662

Claim:
A flexible scintillation-type radiation detector for use in combination with a source of nuclear radiation as a level sensing gauge, comprising: an elongated flexible tube having first and second closed ends and defining therein a scintillation chamber; liquid scintillation material substantially filling the scintillation chamber; said first closed end including a substantially optically-transparent first end closure member; photodetection circuitry operably positioned relative to the first end closure member to quantitatively detect scintillating photons generated in the scintillation liquid indicative of radiation passing into the scintillation chamber; an opaque, flexible protective sheath substantially surrounding the flexible tube; further comprising an expansion chamber for accommodating volumetric expansion of the liquid scintillation material; and wherein a slidable piston member is operably positioned in the scintillation chamber to define a variable volume expansion chamber free of liquid scintillation material adjacent to the second end.