4 Comparative Analysis of the International Status of Acoustic …
47
force of the loading screw, which produces an impact on a large steel transfer block.
The sensor under test is calibrated by a standard transducer. The frequency spectrum
of the sensor under test is obtained by data processing. The primary calibration
devices are shown in Fig. 4.1. The secondary calibration method is a little simpler
than the primary calibration, but it still needs to use the glass capillary tube breaking
source, a primary calibrated reference sensor and a steel block to calibrate the sensor
under test. The diagram of the test device is shown in Fig. 4.2.
Because the above calibration methods require the use of a huge steel block and
fine glass capillary tube, also the test methods are complicated, most sensor users do
Fig. 4.1 Apparatus for the
primary calibration of AE
sensors
Fig. 4.2 Apparatus schematic of the secondary calibration of AE sensors
47
force of the loading screw, which produces an impact on a large steel transfer block.
The sensor under test is calibrated by a standard transducer. The frequency spectrum
of the sensor under test is obtained by data processing. The primary calibration
devices are shown in Fig. 4.1. The secondary calibration method is a little simpler
than the primary calibration, but it still needs to use the glass capillary tube breaking
source, a primary calibrated reference sensor and a steel block to calibrate the sensor
under test. The diagram of the test device is shown in Fig. 4.2.
Because the above calibration methods require the use of a huge steel block and
fine glass capillary tube, also the test methods are complicated, most sensor users do
Fig. 4.1 Apparatus for the
primary calibration of AE
sensors
Fig. 4.2 Apparatus schematic of the secondary calibration of AE sensors