1. Calibration, Temperature & Percent Error

2. What is Calibration?
Calibration of any measuring device is: distance between two closest lines
(Not distance between two closest #’s!)

3. Not all graduated cylinders calibrated same way

4. Large graduated cylinder:
? capacity
? calibration
1000 ml
10 ml

5. ? calibration
1 ml

6. ? calibration
1 ml

7. ? calibration
0.2 ml

8. Here are some other pieces of lab equipment
Here are some other pieces of lab equipment. Can you figure the calibration of each?

9. meter stick: two closest lines
are 1 millimeter apart

10. ? calibration
25 ml

11. This is a quadruple beam balance

12. What’s the calibration?
0.01 gram

13. This is a buret ? calibration 0.1 ml
Note: unlike graduated cylinder, numbers go down, so you read downwards

14. Temperature Scales

15. Scientifically speaking …
The definition of temperature:
Temperature is measure of average kinetic energy of particles in system

17. World’s Record Cold Temperatures
Date ˚F ˚C
World (Antarctica): Vostok II /21/ – –89
Verkhoyansk, Russia (Siberia) 2/7/ – –70
Asia: Oimekon, Russia /6/ – –68
Greenland: Northice /9/ – –66
No A: Snag, Yukon, Canada /3/ – –63
US: Prospect Creek, Alaska /23/ – –62
US: (other than AK)
Rogers Pass, Mont /20/ – –56.5

18. Conversion formulas K = °C + 273 (more precisely 273.15) °C = K – 273
How can we convert from one temperature scale to another?
K = °C (more precisely )
°C = K – 273
[F = (9/5 °C) + 32]

19. Errors are inevitable and need to be dealt with …

20. Percent Error Ratio of error to accepted value % error = Error x 100%

21. Error measured value – accepted value x100% accepted value
absolute value: always positive

22. Data table
Students asked to find density of sucrose [Sucrose has density of 1.59 g/cm3]
1.71
1.45
1.57
Trial 3
1.69
1.68
1.60
Trial 2
1.70
1.40
1.54
Trial 1
Student C
(g/cm3)
Student B
Student A

23. Let’s calculate the error
0.12
0.14
0.02
Trial 3
0.10
0.09
0.01
Trial 2
0.11
0.19
0.05
Trial 1
Student C
(g/cm3)
Student B
Student A
Remember, error is always positive number

24. Now let’s calculate % error
7.5
8.8
1.26
Trial 3
6.3
5.7
0.63
Trial 2
6.9
11.9
3.14
Trial 1
Student C
error
Student B
Student A
% error

25. Advantage of % Error
easier to compare data, especially if comparing data from different trials