1. Measures and their Errors Flashcards
(42 cards)
Accuracy
A measure of how close a measurement is to the true value
Precision
A measure of how close a measurement is to the mean value
Random Error
Unpredictable and unavoidable variations that occur when measurements and observations are being taken
Random Error examples
- Temperature
- A person’s method
- Fluctuations in equipment sensitivity
Systematic Error
Consistent and repeatable errors that occur every time a measurement is taken, cannot be corrected by repeat readings
Systematic error examples
- Zero Error
- Magnetic Fields
- Parallax Error
How to reduce Random Errors
Take repeat measurements and calculate a mean
How to reduce systematic error
Calibrate instruments
Repeatability
Another person can repeat the same experiment with the same method and equipment and get the same results
Reproducibility
Another person does the same experiment using a different method and equipment and gets the same results
Resolution
The smallest change in a measured quantity that an instrument can detect
Higher resolution means it can detect smaller differences
Uncertainty
The interval that a value is said to lie within, with a given level of confidence
What are SI units
Fundamental Units used by every physicician
Mass unit
Kg
Length
m
Time
s
Amount of Substance
mol
Temperature
K
Electric Current
A
Tera (T)
10*12
Giga (G)
10*9
Mega (M)
10*6
Kilo (k)
10*3
Milli (m)
10*-3
