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3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods. Example D : Null measurements. Let us first define some new terms that describe the interface of a measurement system:.
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3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example D: Null measurements Let us first define some new terms that describe the interface of a measurement system: • the transducer is any device that converts a physical signal of one type into a physical signal of another type, • the measurement transducer is the transducer that does not destroy the information to be measured, • the input transduceror sensor is the transducer that converts non-electrical signals into electrical signals, • the output transducer or actuator is the transducer that converts electrical signals into non-electrical signals. Reference: [1]
3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example D: Null measurements Input transducer (sensor) Non-electrical signal Sensor Electrical signal ES N-ES
3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example D: Null measurements Output transducer (actuator) Electrical signal Actuator Non-electrical signal N-ES ES
3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example D: Null measurements Measurement system interface Measurement System Sensor Actuator Non-electrical signals Non-electrical signals Sensor Actuator
3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example D: Null measurements Our aim in this example is to eliminate temperature drift in the sensitivity of a dc magnetic field sensor with the help of a linear temperature-insensitive reciprocal actuator. Reference (Helmholtz coils) Ha VS Vo Hact Sensor Actuator Vs Hact T1 T2 T1 T2 Ha Vo
3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example D: Null measurements Any ideas?
3. MEASUREMENT METHODS. 3.1. Deflection, difference, and null methods Example E: Difference measurements Any ideas?