Circuit for measuring source resistance of a sensor
First Claim
1. A method for measuring a resistance of a sensor, the method comprising the steps of:
- injecting a first test current into the sensor;
measuring a substantially stable first voltage level across the sensor when the first test current is present;
injecting a second test current into the sensor, the second test current being substantially equal to but opposite in polarity to the first test current;
measuring a substantially stable second voltage level across the sensor when the second test current is present;
calculating the resistance of the sensor as a function of the measured first voltage level and the measured second voltage level.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus are disclosed for measuring a resistance of a sensor. The apparatus injects a first test current into the sensor and then measures a substantially stable first voltage level across the sensor when the first test current is present. The apparatus then injects a second test current into the sensor, the second test current being substantially equal to but opposite in polarity to the first test current. A substantially stable second voltage level across the sensor is measured when the second test signal is present. Using the first measured voltage level and the second measured voltage level, the apparatus calculates the resistance of the sensor.
104 Citations
24 Claims
-
1. A method for measuring a resistance of a sensor, the method comprising the steps of:
-
injecting a first test current into the sensor; measuring a substantially stable first voltage level across the sensor when the first test current is present; injecting a second test current into the sensor, the second test current being substantially equal to but opposite in polarity to the first test current; measuring a substantially stable second voltage level across the sensor when the second test current is present; calculating the resistance of the sensor as a function of the measured first voltage level and the measured second voltage level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An apparatus for measuring a resistance of a monitoring system comprising a sensor, the apparatus comprising:
-
means for injecting a first test current and a second test current into the sensor, the second test current being substantially equal to but opposite in polarity to the first test current; means for measuring a substantially stable first and second voltage level across the sensor when the corresponding first test current and second test current are present; and means for calculating the resistance of the sensor as a function of the measured first voltage level and the measured second voltage level. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
Specification