A method of calibrating a compass sensor in consideration of a magnetic environment is provided. The detecting part detects whether the engine is activated or deactivated and whether the door is opened or closed. To achieve this, the ultrasonic sensor contains an ultrasonic waveguide that is connected to the piezoelectric transducer and consists of a material with low acoustic damping properties in a temperature range relevant for the area of application of above 200 DEG C, said material being chemically resistant to the melt. The bolt is orderly inserted through the saucer-shaped plate, the machine housing and the annular transformers to fix securely the annular transformers on the machine housing. This takes place such that with simultaneous heating and cooling a basically constant surface temperature of the preform is attained. The drug-loaded resin particle is separated from the solution and dried before recombining the drug-loaded resin particle with the solution to load more drugs onto the drug-loaded resin particle from the solution.