Abstract: A method and an apparatus for measuring the properties of a liquid that exploit the power modulation a laser light beam undergoes due to the retro-reflection of the laser light beam itself towards the laser cavity from which the laser is generated when this laser light is directed towards a transparent conduit through which the liquid for which the properties are to be measured flows, where this power modulation is detected by at least one photodiode arranged downstream of the transparent conduit.

Abstract: An automatic apparatus for heating and frothing milk comprises a device for generating steam for heating the milk, a first high temperature hydraulic circuit, a refrigerating group for maintaining the conservation temperature of the milk, and a second low temperature hydraulic circuit. The refrigerating group includes a milk container and pump for drawing milk therefrom. A first total separation valve separates the second hydraulic circuit from the first hydraulic circuit, a second total separation valve modulates the quantity of air drawn by the pump, a third total separation valve separates both the first hydraulic circuit and the second hydraulic circuit from a milk dispensing circuit, a steam injection device mixes the steam with the frothed milk, and a fourth total separation valve modulates the quantity of steam outlet from the steam generating device. Each total separation valve is provided with an actuator element manufactured with a shape memory alloy.