The system (1) has a parameter detection unit (7) for detecting a parameter e.g. anesthetic filling level, of an anesthetic dispenser (3) at an anesthesia apparatus (2). The detection device includes an apparatus interface unit (10) provided with a complementary metal-oxide semiconductor camera (17) at the apparatus. A passive dispenser interface unit (11) is formed with an image pattern (16) at the dispenser. The image pattern is detected by the camera that operates in a visible spectral range or an infrared range or in a UV range. An optical encoder (13) is provided with a LED (15). The image pattern comprises an optical code e.g. bar code, two-dimensional code and data matrix code.
