Exam 1 Flashcards
(29 cards)
Accuracy
The deviation from a known input as % of full scale
Readability
Closeness of Scale
Least Count
The smallest unit that can be detected
Sensitivity
Output/Input(measured)
Precision
The ability to reproduce a certain reading with a given accuracy(repeatability)
Calibration
-Can improve accuracy up to the precision
-Test/check the instrument against known standards
Resolution
The smallest unit of the quantity under measurement that can be reliably detected
accuracy error
The value of a measured value minus known value
precision error
The value of one reading minus the average readings
Significant Digits
Digits that are relevant and meaningful
NIST
-National Institute of Standards and Technology
-Maintains standards in the US
-Standards: Common Units
3 Stages of a sensor
1) Detector (sensor stage)
2) Intermediate: Amplifier/Filter
3) Final/Terminating Stage (record/readout)
Noise
Unwanted Data
1) Measurement Noise: Noise caused by measurement procedures
2) Noise part of the process dynamics (determined by the type of measurement)
Types of Measurement Noise
1) Environmental
2) Electrical Signal Conditioning System
3) Quantization Noise
Analog
Signal is analogous to a continuous physical process
Digital
Digital Signal is a set of discrete numbers
Static vs Dynamic
1) Static: Constant in Time
2) Dynamic: Varying in Time
Measurement Errors
-Total error in a set of measurements obtained under controlled or fixed conditions
1) Systematic Errors: Will shift the sample mean from the true mean by a fixed amount
2) Random Errors: Cause a distribution of measured values about the sample mean
Rise Time
The time to from 10 to 90% of full scale
Complete Response
5 Time Constant
Thermocouple
A measurement device that measures a delta V because of a change in temperature
-A junction between two dissimilar metal wires
Thermopiles
Multiple-Junction thermocouple circuits
Resistance Temperature Detector(RTD)
A measurement device that measured the change in resistance due to a change in temperature
Low Pass Filter
A filter that allows low-frequency signals to pass
