Measuring Device, Especially Temperature Measuring Transducer
AssigneeSiemens Aktiengesellschaft
InventorsDirk Burmeister, Eric Chemisky
Life of this patent
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Abstract
The invention relates to a measuring device, in particular a temperature measuring transducer, comprising an electrical resistor, which alters its value based on a chemical or physical variable that is to be measured and which is connected to an evaluation device via at least three lines. Said evaluation device checks the lines for line breaks and if such a break has occurred, switches from a four-wire circuit to a three- or two-wire circuit as required, in order to permit the continuation of the measuring operation. This improves the reliability of the measuring device.
Claims21
1-6. (canceled)
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 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.
A method for measuring a temperature, comprising:
- applying a current to an electrical resistor having variable resistance that depends on temperature;
- evaluating an associated voltage drop across the variable resistor via an evaluation device connected to the variable resistor by 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;
- and
- correlating the evaluated voltage drop of the variable resistor with the associated temperature to be measured.
Dependencies are inferred from the claim text.