1. 1.5 Uncertainty in Measurement

2. Why no measurement is ever certain
Measuring instruments are never completely free of flaws.
Measuring always involves estimation.

3. The last digit of ANY good measurement is…
Estimated!
What about digital instruments?
Still estimated!

4. When you make measurements…
You should know the scale of your instrument.
You should make an estimate one place behind the certain digit.

5. Graduated cylinders
Meniscus: the curved surface of water or other liquids in a cylinder
How do you read it them? Top? Bottom? Middle?
You read the meniscus at the bottom.

6. Accuracy vs. precision
Accuracy: how close a measurement agrees to the accepted value
Precision: repetition of a measurement