Abstract: A method of contactless detection of indications of psychoactive components in a liquid and an apparatus therefor, by emitting a substantially monochromatic light at least at two different wavelengths and detecting the reflection in a free surface of the liquid by a photo detector, analyzing an output signal from the photo detector to identify output parts caused by light emitted from the first and second emitters, respectively, and determining whether the liquid contains at least one psychoactive component.

Abstract: A measurement device (11) is disclosed for measurement of a flow of urine (7) in a flexible tube (4), the device (11) comprising jaws (12, 13) arranged for receiving a section of the tube (4), the device (11) further comprises an arrangement (14, 15, 6) for directing light through the tube (4) in said first direction so as to perform said measurement. A measurement tube (20) is also disclosed having a measurement area (22) within substantially parallel inner walls (23) with a distance in the range of to 4 millimetres as well as the use of the measurement tube (20) with the device (11).