| abstract |
A method and an arrangement for identifying liquid levels, in which method a capacitor is arranged into liquid in a container, between plates of which capacitor, liquid will enter in such a manner that the liquid-filled portion of the space between the plates changes with liquid levels and determines the capacitance of the capacitor. In the invention, a signal obtained from the capacitor is employed, the signal being dependent on the liquid level in the container. A coil is connected to the capacitor forming an electrical circuit with the capacitor, whereby the liquid level, while determining the capacitance of the capacitor, at the same time determines the resonance frequency of the electrical circuit. The resonance frequency is measured from outside the container inductively without a lead-through to the container. |