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Q. Lei et al.
37.3 Experimental Platform and Experimental Program
Design
In order to carry out the principle experiment research, a leak detection experimental
platform was built, which is composed of a leak generating system and a signal
acquisition system. The leak generating system is mainly composed of a vacuum
pump, a bellows, a vacuum-to-plate adapter and a test plate with leak holes, as
shown in Fig. 37.2. Three circular leak holes with different sizes of 1.0, 1.5 and
2.0 mm are premade on the test plate. The minimum leak rate of this system is about
1 Pa m
3 /s.
The signal acquisition system realizes the acquisition, analysis and processing of
the leak acoustic signal, which is composed of some sensors, some preamplifiers,
an acoustic emission acquisition instrument and a computer. The RS-2A acoustic
emission sensor is used in the experiment and its effective frequency band is 100–
400 kHz, and the frequency response curve is shown in Fig. 37.3. The preamplifier
can achieve 40 dB gain amplification; the acoustic emission acquisition instrument
Vacuum pump
Pre-amps
Signal acquisition
device
PC
Valve
Vacuum-to-plate adapter
Leak hole
Sensor
Leak experiment system
Signal acquisition system
Test plate
(a) Schematic diagram
Test plate with stiffener
Vacuum pump
Vacuum nozzle
Pre-amplifier
Digital recorder
(DS-16A)
Computer
(b) Physical map
Fig. 37.2 Leak detection experiment platform