Operating Manual

Important Notice
Guide to Ultrasonic Inspection of Fasteners Page v
Contents
Chapter 1: Ultrasonic Measurement of
Fasteners................................................................. 1
1.1 Important Concepts ....................................... 1
1.1.1 Acoustic Velocity ................................. 1
1.1.2 The Use of Ultrasound ........................ 1
1.1.3 Initial Pulse and Multi-Echo
Measurement Modes .......................... 2
1.1.4 Time of Flight and Ultrasonic Length .. 2
1.1.5 Tensile Load........................................ 3
1.1.6 Stress .................................................. 4
1.1.7 Elongation ........................................... 4
1.1.8 Modulus of Elasticity (Eo) ................... 4
1.1.9 Stress Factor (K) ................................ 5
1.1.10 Temperature Coefficient (Cp)............ 6
1.1.11Calibration-Group Correction
Factors — Stress Ratio and Offset .... 6
1.1.12 Fastener Geometry ........................... 6
1.2 Principles of BoltMike Operation ................... 7
1.3 Practical Limitations Of Ultrasonic
Measurement ................................................ 8
1.3.1 Material Compatible with Ultrasonic
Inspection ............................................ 8
1.3.2 Significant Fastener Stretch ............... 8
1.3.3 Fastener End-Surface Configuration . 9
1.3.4 The Limitations of I.P. and M.E.
Measurement Modes .......................... 9
Chapter 2: Fastener Preparation ...................... 11
2.1 Fastener End-Surface Machining ............... 11
2.2 Methods Of Transducer Placement ............ 12
2.2.1 Practical Methods ............................. 12
2.2.2 Fixtures for Non-Magnetic Fasteners14
Chapter 3: Transducer Selection ...................... 15
3.1 General Acceptability .................................. 15
3.2 Transducer Frequency ............................... 15
3.3 Transducer Diameter .................................. 15
Purpose of Instrument and Transducer
Zeroing ........................................................ 15
Chapter 4: Temperature Compensation .......... 17
4.1 Measuring Fastener Temperature .............. 17
4.2 Limits of Accurate Temperature
Measurement .............................................. 17
4.3 Adjusting the Temperature Coefficient ....... 18
Chapter 5: Selecting Phase ............................... 19
Chapter 6: Fastener Geometry.......................... 21
6.1 Approximate Length .................................... 21
6.2 Determining Effective Length...................... 21
6.3 Fastener Cross-Sectional Area .................. 24
Chapter 7: Material Constants .......................... 25
7.1 Standard Material Constants ...................... 25
7.2 Custom Material Constants ......................... 25
7.3 Selecting a Material Constant ..................... 25
7.4 Material Variations ....................................... 26
Chapter 8: BoltMike Formulas........................... 27
Appendix: Tabular Data ....................................... 29