Lecture 2 units and significant figures
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This document discusses units and significant figures in measurements, rounding off numbers, field notes, and suggestions for recording field notes. It contains the following key points: 1. It discusses the English and metric systems of units of measurement and how to determine the number of significant figures in a measurement. 2. It provides guidelines for rounding numbers and performing calculations while maintaining the correct number of significant figures. 3. It describes the purpose and requirements of field notes, including accuracy, integrity, legibility and arrangement. It also lists the types of field books and notes that are commonly used. 4. It provides 25 suggestions for properly recording field notes in a clear and organized manner.
Lecture 2 units and significant figures
- 1. UNITS AND SIGNIFICANT FIGURES Dr. Mahmood Arshad Assistant Professor, Dept. of Mining Engineering, Faculty of Earth Sciences and Engineering, University of Engineering & Technology, Lahore. smarshad@uet.edu.pk Min-E-240 Surveying Lecture 2 – January 24, 2019
- 3. UNITS OF MEASUREMENT English and metric systems
- 4. Significant Figures The number of significant figures in any observed value includes the positive (certain) digits plus one (only one) digit that is estimated or rounded off, and therefore questionable. Zeros at the end of an integer. For addition, subtraction, multiplication, and division: 1. identify the column containing the rightmost significant digit in each number being added or subtracted, 2. perform the addition or subtraction, and 3. round the answer so that its rightmost significant digit occurs in the leftmost column identified in step (1)
- 5. ROUNDING OFF NUMBERS When the digit to be dropped is lower than 5, the number is written without the digit. Thus, 78.374 becomes 78.37. Also 78.3749 rounded to four figures becomes 78.37. When the digit to be dropped is exactly 5, the nearest even number is used for the preceding digit. Thus, 78.375 becomes 78.38 and 78.385 is also rounded to 78.38. When the digit to be dropped is greater than 5, the number is written with the preceding digit increased by 1. Thus, 78.386 becomes 78.39.
- 6. FIELD NOTES The records of work done in the field measurements, sketches, descriptions, and many other items of miscellaneous information
- 7. GENERAL REQUIREMENTS OF HANDWRITTEN FIELD NOTES Accuracy Integrity Legibility Arrangement Clarity
- 12. TYPES OF FIELD BOOKS Hardbound and loose leaflet. Advantages of loose-leaf books: Assurance of a flat working surface, Simplicity of filing individual project notes, Ready transfer of partial sets of notes between field and office, Provision for holding pages of printed tables, diagrams, formulas, and sample forms The possibility of using different rulings in the same book, and A saving in sheets and thus cost since none are wasted by filing partially filled books.
- 13. KINDS OF NOTES Four types of notes are kept in practice: Sketches, Tabulations, Descriptions, and Combinations of all. The upper part of the left or right page must contain the following items: Project name, location, date, time of day (A.M. or P.M.), and starting and finishing times. Weather. Wind velocity, temperature, and adverse weather conditions Party: The names and initials of party members and their duties are required Instrument type and number.
- 14. SUGGESTIONS FOR RECORDING NOTES Consider it as Homework 1: Handwrite all 25 suggestions under the title “SUGGESTIONS FOR RECORDING NOTES” in Chapter 2 of textbook and submit hardcopy. Solve the exercise questions in Chapter 1 and Chapter 2: Divide you roll number by 3 and get the remainder, i.e., 0, 1, or 2. Solve all questions from the assigned chapters that give the same remainder as in your roll number when question number is divided by 3.
- 15. DATA COLLECTORS