The invention relates to a device for detecting and monitoring ingredients or properties of a measurement medium, for example physiological blood values, wherein said device contains a light source for generating broad-spectrum measurement light and for acting on a measurement area, and means for fanning out the analysis light reflected by the measurement area. The polysaccharide solution is finely divided by mechanical means into spherical droplets which are allowed to pass through a humid atmosphere and transferred to a capturing medium while controlling the temperature and humidity of humid atmosphere. An encrypted session is started early by the atomic operation, before encryption is required.