Safety device for monitoring a technical installation with a pressure-sensitive sensor

A method for determining an output signal of a pressure sensitive sensor including a plurality of first electrodes and a plurality of second electrodes, wherein each first electrode overlaps each second electrode in an associated coupling site and wherein each first electrode in the associated coupling site is spaced apart from the associated second electrode by a pressure sensitive material such that upon application of a force at the coupling site an electrical resistance changes between the associated first electrode and the associated second electrode, the method comprising the steps of:

• providing measuring circuitry coupled to the plurality of first electrodes and the plurality of second electrodes and successively determining the electrical resistance at the associated coupling sites;
• and
• providing an output signal as a function of the measured electrical resistances by an evaluation unit;
• wherein the measuring circuitry is configured, for determining the electrical resistance at a coupling site via the associated first electrode and the associated second electrode, to connect remaining first electrodes not associated with the coupling site and the remaining second electrodes not associated with the coupling site to a terminal for receiving a common potential to enable isolated measurement of the electrical resistance at the coupling site;
• and
• wherein the evaluation unit is configured to, for each coupling site:
• select from among a first output signal, a second output signal, and a third output signal based on a measured voltage of the coupling site, and
• output the selected one of the first output signal, the second output signal, and the third output signal.

A method for determining an output signal of a pressure sensitive sensor including a plurality of first electrodes and a plurality of second electrodes, wherein each first electrode overlaps each second electrode in an associated coupling site and wherein each first electrode in the associated coupling site is spaced apart from the associated second electrode by a pressure sensitive material such that upon application of a force at the coupling site an electrical resistance changes between the associated first electrode and the associated second electrode, the method comprising:

• for a selected coupling site:
• connecting an associated one of the first electrodes to a first potential;
• connecting remaining ones of the first electrodes to a terminal for receiving a common potential;
• connecting an associated one of the second electrodes to a second potential;
• connecting remaining ones of the second electrodes to the terminal;
• measuring a voltage at the selected coupling site;
• and
• in response to the measured voltage, selecting one of a first output signal, a second output signal, and a third output signal for generation as the output signal.