A lighting device includes a lens portion and a base portion. The method comprises an indirect measuring of the flow rate through the following steps of: acquiring at least one pump operation variable; -comparing the value of said variable with a predetermined correlation table to hydraulic flow rate values and determining a corresponding flow rate value. Also disclosed is another acetaminophen formulation containing polyvinylpyrrolidone as high as 25-50% by weight. The write pole is located upstream from the first auxiliary pole relative to a perpendicular magnetic recording medium.