Errors in Measurement. No Measurement is Accurate! Errors occur because of: Parallax error (incorrectly sighting the measurement). Calibration error (if.

Slides:



Advertisements
Similar presentations
All measurements have some degree of uncertainty
Advertisements

1 Press Ctrl-A ©G Dear2009 – Not to be sold/Free to use Errors in Measurement Stage 6 - Year 12 General Mathematic (HSC)
Uncertainty in Measurements
1.1 Fractions: Defining Terms
L Chedid 2008 Significance in Measurement  Measurements always involve a comparison. When you say that a table is 6 feet long, you're really saying that.
Topic 11: Measurement and Data Processing
Errors and Uncertainties © Christopher Talbot and Cesar Reyes 2008
Errors in Measurement Muhajir Ab. Rahim
Unit 1 Significant Figures.  When does = 4?  When 2 = 1.7 rounded  & 3 = 2.6  = 4.3 = 4.
The ± 1 second is called the absolute uncertainty Every measurement has an uncertainty or error. e.g. time = 5 seconds ± 1 second There are three main.
More partial products Recall that we can use a drawing of a rectangle to help us with calculating products. The rectangle is divided into regions and we.
0-12 Mean, Median, Mode, Range and Quartiles Objective: Calculate the measures of central tendency of a set of data.
Which point is located at 3½ ? A B CD Point C is located at 3½.
Accuracy and Precision
CHAPTER 36 Averages and Range. Range and Averages RANGE RANGE = LARGEST VALUE – SMALLEST VALUE TYPES OF AVERAGE 1. The MOST COMMON value is the MODE.
1 Accuracy & Precision Press Ctrl-A ©2009 – Not to be sold/Free to use Stage 4 - Year 7.
Precision Measurement. Describing Measurements Accuracy –How close a measurement is to the true value or quantity. Precision –The degree of exactness.
Data Analysis Mean, Median, Mode and Box and Whisker.
Rounding Round to the nearest whole number 1.4
1 Press Ctrl-A ©G Dear 2008 – Not to be sold/Free to use Relative Error Stage 6 - Year 11 General Mathematics Preliminary.
Scale Reading Basics Scale Reading Basics
Measuring and Significant Digits. Parallax Error Parallax is the apparent shift in position of an object caused by the observer’s movement relative to.
Measurement Science 10. Measurement and Precision Measurements are always approximate Measurements are always approximate There is always some error involved.
Uncertainty and Error in Measurement (IB text - Ch 11) (If reviewing this slide in the senior year, there is also uncertainty information in the AP text.
1 Accuracy and Precision Notes Chemistry 1. 2 Uncertainty in Measurements There is no such thing as a perfect measurement! All measurements have a degree.
Measurements  Dimensions  Volume  Mass Miss Fogg Fall 2015.
Warm-up: Are these “errors”? 1. Misreading the scale on a triple-beam balance 2. Incorrectly transferring data from your rough data table to the final,
Errors and Uncertainties In Measurements and in Calculations.
Chapter Using Metric Units for Length You will need your data pages to complete the following. Only use these not your text for conversions.
Circle Terminology. Circle The set of points in a plane that are a fixed distance from a given point called the center of the circle.
Errors and Uncertainties
Refers to the degree of exactness. The marks on a scale or other instrument tell you the precision that is possible.
1.4 UNDERSTANDING MEASUREMENTS.  Determination of the actual value for particular physical quantity.
© SSER Ltd. How Science Works Selecting & Using Apparatus.
Experimental Errors and Uncertainties
Systematic Errors Units and Measurement Systematic Errors.
Uncertainty2 Types of Uncertainties Random Uncertainties: result from the randomness of measuring instruments. They can be dealt with by making repeated.
Chapter 11: Measurement and data processing Objectives: 11.1 Uncertainty and error in measurement 11.2 Uncertainties in calculated results 11.3 Graphical.
Counting #’s vs. Measured #’s Counting numbers – when we can exactly count the # of objects and there is no UNCERTAINTY in the values Example: Exactly.
Precision and Accuracy When making measurements, a scientists have to evaluate their data. One way is to look at the precision and accuracy. Precision.
Objectives  Distinguish between Accuracy and Precision.  Determine the Precision of Measured quantities.
Upper and Lower Bounds. Upper and Lower Bounds of Measurement. If a length is measured as 25cm to the nearest cm this does not mean that the length is.
Precision, Accuracy and Error. Precision When measuring, most of the time our measurements are estimates. How precise are these estimates? Precision is.
STUDY GUIDE: Page 11 -     Q7 Page 12 -     Q , 15 TEXT BOOK:
Reading a vernier caliper
Physics and Physical Measurement
Reading an Architect’s Scale
Cumulative Frequency Diagrams
4.5 Locating Zeros of a Polynomial Function
Measures of Central Tendency & Center of Spread
How to Read and Record Measurements
Day 2. SI Units.
Errors with Continuous data
Measurements and Uncertainties
Measures of Central Tendency & Center of Spread
Experimental Errors Funny.
Errors and Uncertainties
Uncertainty & significant figures
Cronnelly.
Lesson Vocabulary • meniscus: The curved upper surface of a liquid in a tube. • estimate: A process of referencing a physical quantity in terms of a calibration.
Graphing with Uncertainties
Measurement.
Accuracy, Precision, Percent Error, Significant Figures and Rounding
Rounded Off Values Upper and Lower Bounds.
12.4 Box-and-Whisker Plots
©G Dear 2010 – Not to be sold/Free to use
Every number has its place!
Mean.
Errors with Continuous data
Measurement Readings on Lab Instruments
Presentation transcript:

Errors in Measurement

No Measurement is Accurate! Errors occur because of: Parallax error (incorrectly sighting the measurement). Calibration error (if the scale is not accurately drawn). Zero error (if the device doesnt have a zero or isnt correctly set to zero). Damage (if the device is damaged or faulty). Limit of reading of the measurement device (the measurement can only be as accurate as the smallest unit of measurement of the device).

Definitions Limit of Reading: is the smallest unit of measurement on the measuring instrument. The Greatest Possible Error (also called the absolute error): is equal to half the limit of reading. The Upper and Lower Limits: are the smallest and largest value between which a measurement can lie.

Example Different wrenches have their sizes identified as 2.0cm, 3.0cm, 4.0cm etc. Is this just advertising or is there are difference between 2 cm and 2.0 cm?

2 cm or 2.0 cm Which device gave which mment? What range of mments could be classified as 2cm using the top device? What range of mments would be classified as 2.0 cm using the bottom device?

2 cm The measurement has been done to the nearest centimetre (ie limit of reading is the nearest centimetre). The greatest possible error is half a centimetre. The actual measurement lies somewhere between 1.5 cm and 2.5 cm.

2.o cm The measurement has been done to the nearest millimetre or tenth of a centimetre (ie limit of reading is the nearest millimetre). The greatest possible error is half a millimetre (or 0.05 of a centimetre). The actual measurement lies somewhere between 1.95 cm and 2.05 cm.