ASME B89.4.21.1 2020
$98.04
ASME B89.4.21.1-2020: Environmental Effects on Coordinate Measuring Machine Measurements
| Published By | Publication Date | Number of Pages |
| ASME | 2020 | 63 |
This Technical Report discusses important influences of the environment on dimensional and geometric measurements performed using coordinate measuring machines (CMMs), including influences on both the machine and the workpieces to be measured. This Report discusses the thermal effects related to the use of tactile CMMs, but many of these effects are also applicable to optical and other noncontact coordinate measurement systems.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | CONTENTS |
| 6 | FOREWORD |
| 7 | ASME B89 COMMITTEE ROSTER |
| 8 | CORRESPONDENCE WITH THE B89 COMMITTEE |
| 10 | 1 SCOPE 2 INTRODUCTION AND BACKGROUND 2.1 Operating Conditions 2.2 Definition of Environment 2.3 Environmental Effects |
| 11 | 2.4 Users of This Technical Report 3 THERMAL EFFECTS 3.1 Thermal Expansion of Materials Figures Figure 3.1-1 The Effect of Increase in Temperature on Length |
| 12 | 3.2 Differential Thermal Expansion 3.3 The Metrology Loop: A Three-Element System in Coordinate Metrology Figure 3.2-1 Effect of Differential Expansion on Length |
| 13 | 3.4 Bimetallic and Gradient Bending 3.5 Thermal Response Times |
| 14 | Figure 3.5.2-1 Thermal Step Response Tables Table 3.5.2-1 Thermal Step Response Versus Number of Time Constants |
| 15 | Figure 3.5.2-2 Thermal Response of a Simple Body to Temperature Variation |
| 16 | 3.6 Thermal Environment Characteristics Figure 3.5.2-3 Differential Equation of Measuring System: Two-Element Responses |
| 17 | Figure 3.6.2-1 Typical Thermal Cycle |
| 18 | 3.7 Uncertainty Considerations |
| 19 | 4 NONTHERMAL EFFECTS 4.1 Vibration |
| 20 | 4.2 Illumination 4.3 Particulate Contamination 4.4 Electrical Supply 4.5 Humidity |
| 21 | 5 ASSESSING THERMAL EFFECTS 5.1 Temperature Measurement Table 4.5-1 Ferrous Corrosion Development |
| 22 | 5.2 Drift Testing 5.3 Thermal Derating |
| 23 | 6 ASSESSING VIBRATION EFFECTS 6.1 Foundation Vibration Testing (Based on ASME B89.4.22 (ref. [17]) |
| 24 | 6.2 Relative Motion Tests for Vibration 6.3 Instrument Internal Sources Figure 6.1-1 Passive and Active Isolation Systems |
| 25 | 7 MANAGING THERMAL AND VIBRATION EFFECTS 7.1 Instrument Specifications 7.2 Thermal and Other Environment Controls |
| 26 | 7.3 Thermal Compensation |
| 27 | 7.4 Workpiece Handling |
| 28 | 7.5 Interim Testing 7.6 Handling Thermal Influences in Uncertainty Analysis 8 ECONOMIC CONSIDERATIONS 8.1 General |
| 29 | 8.2 Cost Elements to Consider 9 REFERENCES |
| 31 | NONMANDATORY APPENDIX A OVERVIEW ON THE USE OF TEMPERATURE CONTROL FOR METROLOGY OF WORKPIECES A-1 INTRODUCTION A-2 TEMPERATURE CONTROL |
| 32 | Table B-1-1 Thermal Capacitance of Common Engineering Materials NONMANDATORY APPENDIX B EXAMPLES OF THERMAL TIME CONSTANTS B-1 INTRODUCTION |
| 33 | B-2 EXAMPLE 1 — GAGE BLOCK B-3 EXAMPLE 2 — BALL BAR |
| 34 | Figure B-3-1 Change in Ball Bar Length as a Function of Time Table B-3-1 Summary of Surface Area and Volume Table B-3-2 Surface Area and Volume as a Function of Length |
| 35 | Table B-3-3 Ratios of Volume/Area as Function of Length B-4 EXAMPLE 3 — CHANNEL SECTION B-5 EXAMPLE 4 — COMPOSITE FAN BLADE |
| 36 | Figure B-5-1 Measured Temperature Versus Time With Calculated Values Using the Thermal Time Constant, τ, Obtained From a Least-Squares-Error Fit to the Experimental Data |
| 37 | Figure B-5-2 Estimated Soak-Out Time for a Workpiece Coming From a Shop Area at Some Temperature Into a CMM Room With a Nominal Temperature of 20°C B-6 REFERENCES |
| 38 | NONMANDATORY APPENDIX C ILLUMINATION EFFECTS C-1 APPLICATION TO THE MEASUREMENT TASK |
| 39 | Figure C-1-1 Diopters as a Function of Age C-2 ADDITIONAL CONSIDERATIONS |
| 40 | Figure C-1-2 Percent Acuity as a Function of Age |
| 41 | Figure C-2.1-1 Energy Distribution of Fluorescent Lamp |
| 43 | NONMANDATORY APPENDIX D THERMAL THEORY D-1 GENERAL D-2 MECHANISMS FOR HEAT TRANSFER D-3 HEAT TRANSFER RATE D-4 CONVECTION HEAT TRANSFER |
| 44 | Figure D-4-1 Heat Transfer by Convection Showing Air Velocity Profile |
| 45 | Figure D-4-2 Convective Heat Transfer Coefficient, h, as a Function of Velocity Table D-4-1 Typical Values of Convective Heat Transfer Coefficient D-5 CONDUCTION HEAT TRANSFER |
| 46 | Figure D-5-1 Example of Temperature Profile Within a Workpiece D-6 RADIANT HEAT TRANSFER |
| 47 | Figure D-6-1 Part of the Electromagnetic Spectrum |
| 48 | Figure D-6-2 View Factor Between Two Rectangular Faces D-7 REFERENCES |
| 49 | Figure D-6-3 Values of F1–2 for Assumed Values of the Ratio and Angle |
| 50 | Table E-1-1 Thermal Properties of Common Engineering Materials NONMANDATORY APPENDIX E USEFUL THERMAL PROPERTIES E-1 COMMON ENGINEERING MATERIALS E-2 CONVERSION FACTORS |
| 51 | Table E-2-1 Useful Conversion Factors for Thermal Properties |
| 52 | NONMANDATORY APPENDIX F MACHINE DESIGN CONSIDERATIONS F-1 GENERAL F-2 CMM DESIGN COMPONENTS |
| 53 | Figure F-2.3-1 Effect of Differential Expansion Relative to Distance Between Beam Faces |
| 55 | NONMANDATORY APPENDIX G SEISMIC VIBRATION VERIFICATION TESTS G-1 SCOPE G-2 DEFINITIONS G-3 VIBRATION ACCEPTANCE CRITERIA |
| 56 | G-4 INSTRUMENTATION |
| 57 | G-5 TEST PROCEDURES |
| 58 | G-6 CRITERIA ASSESSMENT G-7 REPORT G-8 FIELD INSTRUMENTATION DIAGRAM G-9 REFERENCE |
| 59 | Figure G-8-1 Diagram of Sensor Arrangement and Instrumentation Configuration |
