非接触空中伝播超音波探触子 PHENOMENALLY HIGH EFFICIENCY NON-CONTACT ULTRASOUND TRANSDUCERS

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Non-contact - gas/air coupled -- ultrasonic transducers offered by SecondWave represent the epitome of transducer design. These devices have been under development since 1978, reaching perfection in 1997 with US and several international patents. NCU transducers are based upon piezoelectric phenomena and feature perfect Z-matching for 100% transduction in air from <100 kHz to 10 MHz.

The new NCU transducers generate immense acoustic pressure in air between <100 kHz to 5 MHz. This is the key to Non-Contact Ultrasound and the magnitude of this development. Imagine 2.0 MHz transmission in 25 mm steel (6 orders of magnitude Z mismatch) with only one burst 16 Vpp and 64 dB amplification!

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  • Total freedom from touch or contamination
  • Efficiency rivaling contact transducers
  • High frequency -- <100 kHz to >10 MHz
  • Robust construction
100 kHz. 16 vpp. ZERO dB amplification
100 kHz. 16 vpp. ZERO dB amplification
500 kHz. 16 vpp. ZERO dB amplification
500 kHz. 16 vpp. ZERO dB amplification
1 MHz. 16 vpp. ZERO dB amplification
1 MHz. 16 vpp. ZERO dB amplification
2 MHz. 16 vpp. ZERO dB amplification
2 MHz. 16 vpp. ZERO dB amplification
3 MHz. 16 vpp. ZERO dB amplification
3 MHz. 16 vpp. ZERO dB amplification
10 MHz. 16 vpp. ZERO dB amplification
10 MHz. 16 vpp. ZERO dB amplification

NCU TRANSDUCERS

SPECIFICATIONS
FEATURE SPECIFICATIONS
Frequency Range Sensitivity <100 kHz to >10 MHz
Phenomenally high in air, ~30 dB lower
than contact transducers
Signal to Noise Ratio Bandwidth Generally, >60 dB
Nominally, between 30 to 50% of BCF
- broader bandwidths, also available
Dimensional Range
Geometrical Configuration
Housing
<1 mm to >76 mm active diameter
Planar, point and cylindrically focused
Aluminum protected by clear plastic cover
Co-axial Connector Axially mounted standard BNC
Maximum Humidity 90% RH
Maximum Temperature 70 deg C
Maximum Gas Pressure Successfully tested up to 50 bars
Construction Robust and factory suitable

PLANAR TRANSDUCERS

ORDERING INFORMATION
CATALOG # FREQUENCY ACTIVE DIAMETER (mm)
NCT-101
NCT-201
100 kHz 25.0
50.0
NCT-52
NCT-102
NCT-202
200 kHz 12.5
25.0
50.0
NCT-25
NCT-55
NCT-105
NCT-205
500 kHz 6.3
12.5
25.0
50.0
NCT110
NCT-210
NCT-510
NCT1010
1.0 MHz 3.2
6.3
12.5
25.0
NCT120
NCT-220
NCT-520
2.0 MHz 3.2
6.3
12.5
NCT130
NCT-230
NCT-530
3.0 MHz 3.2
6.3
12.5
NCT140
NCT-240
NCT-540
4.0 MHz 3.2
6.3
12.5
NCT150
NCT-250
NCT-550
5.0 MHz 3.2
6.3
12.5

For assistance and other variables, please contact us.

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FOCUSED NON-CONTACT TRANSDUCERS

Non-contact transducers can also be configured to generate focusing mechanism in air. In the following table we have provided a few point focused transducers. Should you need cylindrically focused transducers, simply change the suffix “P” to “C.” The numeral following the suffix is the Relative Aperture (RA, focal length/active diameter). Very small RA transducers are difficult to produce, however, in special cases we have made transducers with RA of 1.

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ORDERING INFORMATION
MODEL # FREQ. ACTIVE
Ф
(mm)
FOCAL
LENGTH
IN AIR
(mm)
FOCAL
POINT
IN AIR
(~mm)
HALF
ANGULAR
APERTURE
(~o)
NCT-102-P4
NCT-102-P6
NCT-202-P4
NCT-202-P6
200 kHz 25

50
100
150
200
300
7.0
10.0
7.0
10.0
7.2
4.8
7.2
4.8
NCT-105-P4
NCT-105-P6
500 kHz 25 100
150
2.8
4.2
7.2
4.8
NCT-210-P4
NCT-510-P4
NCT-510-P6
1.0 MHz 6.3
12.5
25
50
75
1.4
1.4
2.1
7.2
7.2
4.8
NCT-220-P4
NCT-520-P4
NCT-520-P6
2.0 MHz 6.3
12.5
25
50
75
0.7
0.7
1.0
7.2
7.2
4.8
NCT-230-P4
NCT-530-P4
NCT-530-P6
3.0 MHz 6.3
12.5
25
50
75
0.5
0.5
0.7
7.2
7.2
4.8
NCT-240-P4
NCT-540-P4
NCT-540-P6
4.0 MHz 6.3
12.5
25
50
75
0.35
0.35
0.55
7.2
7.2
4.8
NCT-250-P4
NCT-250-P6
5.0 MHz 6.3 25
38
0.28
0.42
7.2
4.8

For assistance and other variables, please contact us.

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AIR/GAS VELOCITY COMPENSATION NON-CONTACT TRANSDUCERS

In order to increase the stability of ultrasound signals in NCU mode sometimes it may be necessary to compensate for velocity fluctuations in air caused by thermal currents, humidity variations, and turbulent air flow. This is especially true for very accurate thickness, velocity, transmittance, reflectance, and density measurements. While our NCA 1000 with planar transducers is capable of providing accuracies within +/- 1%, with Velocity Compensation (VC) transducers it can be increased by an order of magnitude. VC transducers feature constant distance built-in reflectors in front of active transducers from which the NCA 1000 constantly determines the air velocity to apply to all measurements.

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ORDERING INFORMATION
CATALOG # FREQ.

ACTIVE
Ф
(mm)

TRANSDUCER-
INTERNAL
REFLECTOR AIR
DISTANCE
(mm/round-trip
ToF, μs)
BEAM EXIT
APERTURE
DIAMETER
(mm)
NCT-102-VC 200 kHz 25.0 50/290 19
NCT-55-VC
NCT-75-VC
NCT-105-VC
500 kHz 12.5
19.0
25.0
20/115
20/115
20/115
10
14
19
NCT-510-VC
NCT-710-VC
1.0 MHz 12.5
19.0
10/58
10/58
10
14
NCT-520-VC 2.0 MHz 12.5 5/29 10

For assistance and other variables, please contact us.

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