Method for determining the electrical resistance of an electrical supply lead to sensor elements and a sensor arrangement

1. Method for determining an electrical resistance of an electrical supply lead to sensor elements, in which the sensor elements are interconnected to form a sensor arrangement and in which:

an overall electrical resistance of the supply lead to the sensor elements is determined by measurement, in which case the overall electrical resistance includes both an electrical resistance of an electrical line to the sensor elements and also an electrical resistance of an electronic component which is arranged in a current path specified by the electrical line;

the overall electrical resistance of the supply lead to the sensor elements is compared to a reference value, in which case the reference value is a value of an overall electrical resistance of a reference component of the sensor arrangement and its electrical line;

the reference value is determined through measurement;

the overall electrical resistance of the supply lead to the sensor elements is compared with a further reference value;

the further reference value is a value of an overall electrical resistance of a further reference component of the sensor arrangement and its electrical line;

the further reference value is determined through measurement;

the further reference value represents an upper permitted limit value of the overall electrical resistance of the supply lead to the sensor elements;

the sensor elements are arranged as a matrix of rows and columns;

each row and each column includes an electrical supply lead connected to its sensor elements; and

the overall resistance of the supply lead of each row and column is determined individually by measurement.

2. Method in accordance with claim 1 , in which a signal to a downstream control unit is provided as soon as the upper permitted limit value is exceeded by the measured overall resistance of the supply lead.

3. Method in accordance with claim 1 , in which the reference value represents a lower limit value of the overall electrical resistance of the supply lead to the sensor elements.

4. Method in accordance with claim 3 , in which a signal is provided to a downstream control unit as soon as the lower reference value is undershot.

5. Method in accordance with claim 1 , in which a signal to the downstream control unit is provided as soon as the upper permitted limit value is exceeded by the measured overall resistance of the supply lead.

6. Method in accordance with claim 1 , in which, an overall electrical resistance of the supply lead of each row and of each column of the sensor is compared with a further reference value that is determined by measuring an overall electrical resistance of a further reference component of the sensor arrangement and its electrical line, and that represents an upper permitted limit value of the overall electrical resistance of the supply lead.

7. Method in accordance with claim 6 , in which, for each respective one of the plurality of supply leads of the rows and columns of the sensor elements, the further reference value represents a lower limit value of the overall electrical resistance of the respective one of the plurality of supply leads.

8. An apparatus including:

a flat sensor arrangement having interconnected sensor elements and an electrical supply lead to the sensor elements; and

a control unit for determining an electrical resistance of the electrical supply lead to the sensor elements, wherein the control unit is adapted to:

determine an overall electrical resistance of the supply lead to the sensor elements by measurement, in which case the overall electrical resistance includes both an electrical resistance of an electrical line to the sensor elements and also an electrical resistance of an electronic component which is arranged in a current path specified by the electrical line;

compare the overall electrical resistance of the supply lead to the sensor elements to a reference value, in which case the reference value is a value of an overall electrical resistance of a reference component of the sensor arrangement and its electrical line;

determine the reference value through measurement;

compare the overall electrical resistance of the supply lead to the sensor elements with a further reference value; wherein the further reference value is a value of an overall electrical resistance of a further reference component of the sensor arrangement and its electrical line;

determine the further reference value through measurement wherein the further reference value represents an upper permitted limit value of the overall electrical resistance of the supply lead to the sensor elements; the sensor elements are arranged as a matrix of rows and columns, and each row and each column includes an electrical supply lead connected to its sensor elements; and

determine the overall resistance of the supply lead of each row and column individually by measurement.

9. The apparatus in accordance with claim 8 in which the reference component has a resistance value with a low tolerance compared with the sensor elements.

10. Method for determining an electrical resistance of an electrical supply lead of a flat sensor arrangement, the method which comprises:

providing a flat sensor arrangement having interconnected sensor elements and an electrical supply lead to the sensor elements; and

determining, with a control unit, an overall electrical resistance of the supply lead to the sensor elements by measurement, in which case the overall electrical resistance includes both an electrical resistance of an electrical line to the sensor elements and also an electrical resistance of an electronic component which is arranged in a current path specified by the electrical line;

comparing, with the control unit, the overall electrical resistance of the supply lead to the sensor elements to a reference value, in which case the reference value is a value of an overall electrical resistance of a reference component of the sensor arrangement and its electrical line;

determining, with the control unit, the reference value through measurement;

comparing, with the control unit, the overall electrical resistance of the supply lead to the sensor elements with a further reference value, wherein the further reference value is a value of an overall electrical resistance of a further reference component of the sensor arrangement and its electrical line;

determining, with the control unit, the further reference value through measurement, wherein the further reference value represents an upper permitted limit value of the overall electrical resistance of the supply lead to the sensor elements, the sensor elements are arranged as a matrix of rows and columns, and each row and each column includes an electrical supply lead connected to its sensor elements; and

determining, with the control unit, the overall resistance of the supply lead of each row and column individually by measurement.