DMTA-10022-01EN, Rev. C, January 2015
Using Advanced Gaging Features
151
The gain value appears near the lower-right corner of the display. The waveform
display changes to the amplitude proportional to the gain mode.
2.
Press
[
]
or
[
]
to adjust the gain in ±1 dB steps.
The gain value and the height of the echoes change accordingly.
•
Increase the gain value when the peak amplitude of the echo that should be
detected is below 20 % of the waveform display height.
This prevents the gage from reading too high a value when skipping one
back-wall echo, and from measuring twice the correct thickness (doubling).
•
Reduce the gain value when noise peaks are above 20 % of the waveform
display height.
This prevents the gage from detecting a noise peak rather than the correct
back-wall echo.
3.
Press
[2nd F]
,
[GAIN/WAVE ADJ]
again to restore the default gain value.
4.
Press
[GAIN/WAVE ADJ]
again to return to the automatically adjusted echo
height mode.
The default automatic gain mode is indicated by a blank
Gain
field.
9.2
Adjusting the Extended Blank with Dual Element Transducers
Olympus recommends using the extended blank parameter only if you are an
experienced operator who thoroughly understands the acoustic properties of the
material being measured. Incorrect use of the extended blank can cause the gage to
misread areas of thin material.
Normally, the 45MG searches for echoes down to nearly zero thickness. However,
some special circumstances, such as a high degree of near-surface corrosion,
aluminum material, enclosed flaws, or laminations, can generate echoes that the
instrument may falsely detect as the low thickness. When these echoes are larger than
the sought after back-wall echo, the manual gain adjustment (see “Adjusting the Gain
with Dual Element Transducers” on page 149) cannot prevent this false detection.
However, the extended blank parameter allows you to define an early period, during
which the 45MG will not perform echo detection, thereby preventing erroneous
measurements.
CAUTION
Summary of Contents for 45MG
Page 8: ...DMTA 10022 01EN Rev C January 2015 Table of Contents viii List of Tables 227 Index 229...
Page 26: ...DMTA 10022 01EN Rev C January 2015 Introduction 16...
Page 36: ...DMTA 10022 01EN Rev C January 2015 Chapter 1 26...
Page 42: ...DMTA 10022 01EN Rev C January 2015 Chapter 2 32...
Page 136: ...DMTA 10022 01EN Rev C January 2015 Chapter 6 126...
Page 150: ...DMTA 10022 01EN Rev C January 2015 Chapter 7 140...
Page 157: ...DMTA 10022 01EN Rev C January 2015 Configuring the Instrument 147 Figure 8 3 The COMM screen...
Page 158: ...DMTA 10022 01EN Rev C January 2015 Chapter 8 148...
Page 196: ...DMTA 10022 01EN Rev C January 2015 Chapter 10 186...
Page 208: ...DMTA 10022 01EN Rev C January 2015 Chapter 11 198...
Page 226: ...DMTA 10022 01EN Rev C January 2015 Appendix A 216...
Page 232: ...DMTA 10022 01EN Rev C January 2015 Appendix C 222...
