Patent ID: 7712958

Claim:
A temperature measuring transducer, comprising: a variable electrical resistor having variable resistance that depends on a chemical or physical variable; and an evaluation device connected to the variable resistor by at least three lines through which the lines can be checked for a line break, wherein, for a break in a first of two lines which are connected on the same side of the variable resistor, a measurement of the resistance value using the first line is performed with the second line by routing the current conducted through the variable resistor via the second line and by tapping off the falling voltage associated with the second line, wherein the evaluation device compensates for the influence of the resistance of the second line, and wherein the evaluation device further comprises a control and processing unit and a switchable current source wherein the current source for line checking is switchable to either the first or second line, which are connected to a first side of the variable resistor and that the current flowing through the variable resistor is recorded and evaluated to establish a line break.