1. Review Theory Measurements Measurements help us describe the world and everything in it. Measurements can describe length, volume, weight, time, temperature, and countless other properties. Standardized Unit System Metric system and the English system This work is funded under grant DUE# from the National Science Foundation Advanced Technological Education (ATE) program. Opinions and findings expressed herein are those of the authors and do not necessarily reflect the views of the National Science Foundation. © Copyright 2012 FLATEFLATE 1

Review Theory, Cont. PropertyMetric UnitsEnglish Units Length Meters, kilometersInch, foot, mile Volume cubic centimeterscubic inches Fluid Volume Milliliter, liter Quart, gallon Mass Milligram, gram, kilogram Ounce, pound, ton Temperaturedegree Celsius (˚C) degree Fahrenheit (˚F) 2

Review Theory Accuracy Degree of closeness of measurements results to the true value Precision, reproducibility or repeatability The degree to which repeated measurements of a quantity under unchanged xxx conditions show the same results 3

Review Theory, Cont. Accuracy Degree of closeness of measurements results to the true value Precision, reproducibility or repeatability The degree to which repeated measurements of a quantity under unchanged conditions show the same results 4

Review Theory, Cont. Accuracy & Precision Examples High Accuracy - Low Precision High Precision - Low Accuracy True Value 5

1a. Exercise How accurate & Precise are U? 6

1b. Tolerance Interval / Margin Error Example: Let’s measure Flater using a ruler: Ruler’s precision: 1/16 (0.063 un) Tolerance interval: 2.25 ± un Hi, My name is Flater! 7

Measuring Tools & Their use Figure 4. Long distance measuring tape 8 Figure 1. Ruler Figure 2. Flexible measuring tape Figure 3. Caliper

Sample of Measuring Tools Cont. Graduated cylinder, measuring cup, water velocity-meter, thermometer, analytical balance 9

Measuring Tools Calibration Measuring devices should be calibrated against standards Example: A set of metric gauge blocks 10

Exercise: Measuring Tools & Units Which measuring tool and units you will use to measure: 1. Classroom 2. Desk 3. Pencil 11

2. Part A - U Measure it a)Use paper ruler (fig.1), Surgical blade (fig. 10) and Reciprocating Action Blade (fig. 11) and provide the following dimensions: Surgical Blade – figure 10: total and 1/2 of the surgical blade length, the widest part of the blade, and separation between teeth. Reciprocating Action Blade – Figure 11: total length L, outside diameters D 1, D 2, and D 3, as indicated in figure 11. Write the results for each measurement in tables 1 and 3 respectively 12

2. Part A - U Measure it. Cont. b) Use a normal ruler or any other more precise measuring tool, (optional). Measure the same points described in (a). In addition, for the surgical blade measure angles between the teeth, angles 1, 2, and 3. See figure 10 for details. Write the results in table 1, 2, and 3 accordingly. Prepare a graphical chart to represent “accuracy” and “precision” of the data, (see figures 8 – High accuracy Low precision and figure 9 – High Precision Low Accuracy). Compare results from exercise (a) and (b). 13

2. Part A - U Measure it. Cont. c) Compare results from (a: paper ruler) and (b: accurate ruler) in terms of accuracy and precision Table 1. Measurements of Surgical Blade Group No. Total Height (cms) ½ Height (cms) Widest part (cms) Separation between teeth (mm ) Paper ruler Normal ruler Paper ruler Normal ruler Paper ruler Normal ruler

2. Part A - U Measure it. Cont. 15 Group No Table 2 - Exercise 2b and 2c Surgical Blade – Angle Measurements in degrees (o) Angle between teeth Angle 1Angle 2Angle

2. Part A - U Measure it. Cont. 16 Table 3 - Reciprocating Action Blade Measurements for exercises 3(a), 3(b), and 3(c) Reciprocating Action Blade Measurements Group No. Total length - L (centimeters) Diameter D1 (centimeters) Diameter D2 (centimeters) Diameter D3 (millimeters) ruler 1 figure 1 ruler 2 normal ruler ruler 1ruler 2ruler 1ruler 2ruler 1ruler

U Measure it Cont. d) Accuracy and precision: of students should mark a dot representing the total length obtained in the exercises 2a and 2b. Accuracy: how close the individual measurements of the total length of the surgical blade agree with the correct value. Precision: check for reproducibility of measurements between groups. e) Report at least the one dimension of the surgical blade in exercise (b) using 3 significant figures and the respective tolerance interval. Example: 2.3 ±0.05 cm or from 2.25 cm to 2.35 cm. 17

Exercise 3. Part B-Zero Waste Surgical Blade- U Design it Figure 10 Use the surgical blade and reciprocating action blade from example 3 (figure 10 and 11) and a clean sheet of paper (11x8 ½”). a) What are the steps you would need to take if you were designing and manufacturing surgical blades as shown in the picture? b) How many surgical blades can you manufacture from a sheet of paper (8 ½x11”). Consider minimum waste of material and maximum product. Draw the possible options for manufacturing the surgical blade and demonstrate the most efficient-zero waste distribution design. 18

Answers. Zero Waste - U Design it The most efficient-zero waste distribution design: Total19 units 8 blades vertical blades 11 blades in horizontal position 19