1 Introduction
2 Experimental Setup
Transducers | Manufacturer | Centre frequency (MHz) | Diameter (in.) |
---|---|---|---|
1 | IMASONIC | 7.5 | 0.24 |
2 | GE | 7.5 | 0.50 |
3 | GE | 7.5 | 0.50 |
3 Repeatability Test
3.1 Transducer Angle Change
3.2 Transducer Stand-Off
3.3 Test Position
4 Compensation
4.1 Temperature Compensation
4.1.1 Influence of Temperature on Baseline Subtraction
4.1.2 Temperature Compensation Methods
4.1.3 Experimental Results
4.2 Compensation for Transducer Frequency Response Change
4.2.1 Methodology
4.2.2 Experimental Setup
4.2.3 Experimental Results Before and After Compensation
Calibrated/compensated factors (differences between current and baseline signals) | Improvement level (dB) |
---|---|
Re-setup | |
Angle | 18 |
Stand-off | 17 |
Angle, Stand-off and Lateral positions | 15 |
Temperature (10 \(^\circ \)C test temperature change between baseline and current) | 11 |
Transducer frequency response change (with the same transducer; relatively simple frequency spectrum; a peak frequency difference of ±250 kHz from a baseline value of 7 MHz) | 14–20 |
Transducer frequency response change (with different transducers, thus including all above factors due to transducer re-setup; relatively simple frequency spectrum; a peak frequency difference of ±250 kHz from a baseline value of 7 MHz) | 10 |