The invention relates to the recording of soundtracks onto analogue cinema film, in particular the recording of digital created andor digitalelectronically stored representations of soundtracks onto film. A suspended microchannel resonator is calibrated to determine the relationship between a detected mass and a resonance frequency shift of the resonator. A plurality of circumferentially arranged, spaced-apart parallel ridges project outwardly from a surface of the cylindrical tube. The lid includes a body for covering at least a portion of the container opening and a skirt depending from the body portion. When the rotational component rotates, the rotational component drives the transmission component so as to make the shaft rotate and make a coil generate an induced current. The focal length of the first lens element is f1, the focal length of the optical lens system is f, and they satisfy the relations: ff1<0.