| 摘要 |
<p>An ionised active principle solution is impregnated into a layer (2) forming part of a container (1). The amount of active principle contained in the layer may be determined by measuring the conductivity of said layer. The measuring device includes (a) first (7) and second (10) electrodes arranged on either side of and in electrical contact with at least one portion of the impregnated material layer (2) in the container; (b) a component (5) for causing a flow of electric current having a predetermined strength through the impregnated material; and (c) a component (6) for sensing the voltage (V) between the electrodes (7, 10) and calculating the amount of active principle in the container.</p> |
