Abstract: The invention provides a fragrance delivery system comprising: a control unit for controlling a release mechanism to release at least one selected fragrance, said control unit comprising a selection unit for selecting said selected fragrance from at least two fragrances and controlling said release mechanism to release said selected fragrance, and a switching element for switching said release mechanism between an first state and an second state or vice versa, in which first state said release mechanism releases said selected fragrance at a higher rate than in said second state. The invention further provides a kit of parts comprising said device and a at least two fragrance reservoirs filled with a fragrance chemical.

Abstract: Method of estimating a level of fluid that is absorbed by a porous substrate, wherein fluid is absorbed by the substrate, wherein a light is arranged near the substrate such that it emits light rays directed to the substrate, wherein the light intensity of the light rays transmitted through the substrate changes under influence of the decrease of the amount of fluid that is absorbed by the substrate.

Abstract: The invention provides a fragrance delivery system comprising: a release mechanism for releasing at least one fragrance, and a control unit for controlling said release mechanism, said control unit comprising a selection unit for selecting said fragrance from at least two fragrances in response to turning on said fragrance delivery system. The invention further provides a kit of parts comprising said device and a at least two fragrance containers filled with a fragrance substance. In addition, the invention relates to the use of a release mechanism for releasing at least one fragrance and a control unit for controlling a release mechanism, said control unit comprising a selection unit for selecting said fragrance from at least two fragrances in response to turning on said fragrance delivery system.

Abstract: The invention provides a fragrance delivery system comprising: a control unit for controlling a release mechanism to release at least one selected fragrance, said control unit comprising a selection unit for selecting said selected fragrance from at least two fragrances and controlling said release mechanism to release said selected fragrance, and a switching element for switching said release mechanism between an first state and an second state or vice versa, in which first state said release mechanism releases said selected fragrance at a higher rate than in said second state. The invention further provides a kit of parts comprising said device and a at least two fragrance reservoirs filled with a fragrance chemical.