Fill-level indicator for a liquefied-petroleum-gas tank

Fill-level indicator for use in a liquefied petroleum gas tank, comprising:

• an array of optical detectors attached to a mount, vertically spaced apart from one another and distributed inside the tank over a height of the tank, each detector including a light source and a receiver, and
• means for feeding power to the light sources of the various detectors, for processing signals arriving at the various receivers and for transmitting signals to a gauge displaying a fill-level of the liquefied gas,
• wherein the mount and the detectors placed thereon are positioned in a casing which is highly transparent to light beams emitted by the light sources and wherein a synthetic resin which is highly transparent to the light beams emitted by the light sources is disposed between one surface of the casing and the detectors for encapsulating the mount and the detectors such that a surface of the resin facing the detectors reflects a light beam emitted by the corresponding light source toward the associated receiver, and
• wherein the casing comprises a material having a refractive index very close to that of the resin.