Optical liquid level detection sensor and liquid overfill prevention system comprising such sensor

An optical liquid level detection sensor, the sensor comprising:

• a light source for emitting a light beam,
• a liquid contact surface, and
• a light detector,
• wherein the light source is arranged to emit a light beam towards the liquid contact surface, which liquid contact surface reflects or transmits the light beam in dependence of liquid being present on the liquid contact surface,
• wherein the light detector is arranged to receive the light beam after reflection on the liquid contact surface, and
• wherein the sensor comprises an at least partially transparent ring element, wherein the liquid contact surface is formed by an outer surface of the ring element,
• wherein at least a part of the ring element forming the liquid contact surface is formed as a prism element,
• wherein the sensor comprises a housing having two or more housing parts,
• wherein sealing elements are arranged between sealing surfaces of the ring element and the two or more housing parts, and
• wherein the sealing surfaces of the ring elements are formed by opposed planar surfaces of the ring element.