Acoustics; Ultrasonic power measurement in the frequency range 0.5~10MHz
Some standard content:
UDC681.8:829.12.051534.62
National Standard of the People's Republic of China
GB 7966--87
0.5～10MHz Frequency Range
AcousticsUltrasonic power measurement in thefrequency range 0.5--10MHz
1987-06 22 Issued
National Standard 1988-04-01 Implementation
1 Introduction
National Standard of the People's Republic of China
0.5~10MHz Frequency Range
Acoustics--Ultrasonic power measurement in thefrequency range 0.5-10MHz
UDC 681.8 : 629. 12
05 -534.62
GH 7966 --87
1.1 The standard specifies the method and technical specifications for the continuous excitation power of the ultrasonic transducer radiated in the body within the frequency range of 0.5 to 10mW.
1.2 The applicable measurement range of the standard is 1W to 20W. According to the actual situation, it should be divided into watt-level and watt-level sections. 1-50mw.
Watt-level: 0.5~20W
1.3 The measurement devices reserved in this standard are divided into the following levels according to the requirements of use and the measurement accuracy: Level 1 Standard measuring device: As the benchmark for measuring the super sound frequency, it is used to measure the standard super source (standard device for transmission) or the occasion where the measurement accuracy is required, and its measurement uncertainty is not more than +5%. Grade 1 standard measuring device is used to approve commercial power transducers, ultrasonic transducers and ultrasonic equipment. Such devices should be easy to move and their measurement uncertainty should not exceed 10%.
1.4 The names and numbers of the terms, letters and numbers used in this standard shall comply with the provisions of national standards such as GB3947-8 (Terms of Acoustics), GB 3102.7-86 (Terms of Acoustics). 1.5 The preparation of this standard refers to the standard "LC160 (1963) "Test and Calibration of Acoustic Therapeutic Equipment". Grade 1 standard measuring device
Grade 1 standard measuring device uses the radiation pressure method to measure ultra-clear sound power. 2.1 Measurement principle
In a small plane ultrasonic field, the average unidirectional pressure on the interface of two media is the radiation force, which is the value of the energy density of the two coplanar media. The radiation pressure generated can be measured by an energy field under an illumination. Ultrasonic transducer The relationship between the total power ratio radiated by the device and the force acting on the reflection is: ef
2cos2f
Total power ratio, w.
The force acting on the sound wave along the line, N: The propagation speed of the sound wave in the liquid, m/5t The angle between the normal line of the surface and the incident beam, (). Let: Target: The cell specimen used to construct the image of the force in the center field. (1)
Double-volume limit shadow Jiang Hao City source, when a: 8 small (is the number of waves entering the body, is the path of the sound transducer), the assumption is that the large double case is not large: 2 The price of the confiscated non-negligible, product: and the state of the warehouse to the zero () 1. The device or, () reduction product to "sent to the National Bureau of Standards 19870622 approved
1988 04-01 implementation
GB 1968-8T
e, where e is the liquid plane sound wave sound pressure spot reduction coefficient, for 23 ℃ water. .-- 2. 3× 10 - f2 .
Wherein, m—the pressure attenuation coefficient of a plane ultrasonic wave in a liquid, f----frequency, MHz.
2.2 Milliwatt wall measuring device
The schematic diagram of the milliwatt wall measuring device is shown in Figure 1. It consists of an automatic electronic microbalance, anechoic water and a reflective target suspension system. The force generated by the milliwatt ultrasonic power is about a few tenths to several hundred micronewtons (equivalent to a few micrograms to tens of millimeters of gravity). In order to reduce the influence of the surface tension of the water and the passiveness caused by the torsion of the target sensing suspension system, the milliwatt device should use a single suspension wire, and the ultrasonic beam should be radiated vertically upward during measurement.
Blood and pancreatic display
GB 1966-87
Figure 1 Schematic diagram of the 100-degree measuring device
1 Micro-disc, 2-radiator, 3-target, 4-degassing benzene, 5-collector, 6-transducer, 7-water regulating mechanism, 8-bracket and flow control, 9-base, 0-spacer, 11-suspending wire 2.3 Assembly and installation
The 100-degree measuring device is similar to the 100-degree measuring device, as shown in Figure 2. The force generated by the 100-degree ultrasonic power is about zero to several 1000 Newtons (then the gravity is about 1000 grams to 1000 grams). The general suspension system uses three suspension wires, and the ultrasonic beam radiates vertically downward during measurement. 3
GB7966-87
Figure 2 Schematic diagram of the milliwatt test device
—Central half or precision splitter 2—Product generator, 3—~ double: 4—Tracking air, 5—Transparent membrane, 6—Reflection age,?—Sound absorbing tip,—Transducer, 9—Bracket and airflow prevention leather: 0—Seat: 1—Image generator, 12·Grid 2. Measuring instruments and main parts
2.*.1 Segment radiator
2.4.1.1 The structure of the milliwatt test device is a hollow rounded chain, as shown in Figure 3. The lower front angle is 90° to measure the power generated by the supermarket transducer when it radiates vertically upward.
GB 786687
2.4.1.2 The structure of the test device is a hollow inverted cone, as shown in Figure 4. The upper cone is a four-conical surface with a vertical angle of 125°~135°, which can measure the force generated when the transducer radiates downward. Figure 3 Schematic diagram of the typical structure of the milliwatt-level reflector target GB7966-B7
4 Schematic diagram of the typical structure of the full-scale reflector
2.4.1,3 The size of the target is 0.2~0.6mm in wall thickness, and the diameter should be greater than 1.5 times the diameter of the ultrasonic transducer radiation surface, and it should be ensured that the entire energy of the sound can be intercepted.
2.4.1.4 The material of the target is stainless steel or copper (which should be electropolished), and the target should have a certain rigidity so that it will not be affected by cavitation caused by static pressure.
The technical requirements of the target should be that the straightness of the cone generatrix is less than 10um, the angle accuracy is less than 10, and the surface roughness is Rao.20μm. The mass distribution is uniform, so that the target is in a stable equilibrium state in the water and there is no deflection when it is vertically oriented. For targets that meet the above conditions, the sound pressure reflection coefficient is greater than 0.97, and the uncertainty of sound power measurement caused by this is not more than 1%. 2.4.1.5 The suspension wire of the target is a nylon wire or metal wire with a diameter not greater than 20μm, and the measurement uncertainty caused by surface tension can be ignored.
2.4.2 Force measuring instrument
2.4.2.1 The milliwatt-level measuring device should use a feedback electric microbalance with a sensitivity of 0.11g and an accuracy of less than 0.1pg, so as to ensure that its sensitivity is better than 1u when measuring force. For a sound power of 11W, the measurement uncertainty caused by this is not more than 1.5%. For a 45° reflective target and a sound power of 1mW, the force corresponding to the force is 68ug of gravity. 2.4.2.2 The watt-level measuring device should use an electronic balance or precision analytical scale with a sensitivity of 0.1 mg, and the accuracy should be better than 0.1 mg. Then, for a sound power of 0.5 W, the uncertainty of the splash caused by this is not more than ±0.2%. Note: For a reflective target with a g=22.5, the force corresponding to a sound power of 0.5 W is a gravity of 58.5 mg. 2.4.3 The inner wall of the water tank should be covered with a sound-absorbing material with an absorption coefficient greater than .99 to ensure the required free field conditions so that the measurement error caused by this can be ignored.
2.4.1 Transparent film
A transparent film should be placed between the ultrasonic transducer and the reflective target. The thickness of the film should be less than 20 μm, and its pressure-transmitting coefficient should be less than 0.995. It should be placed as close to the reflective target as possible. In order to prevent the film from affecting the measurement when reflecting, the film should be tilted at an angle slightly greater than ° to the ultrasonic transducer.
2.4.5 Isolation device
The milliwatt-level measurement device should take vibration isolation measures to ensure that external vibration does not affect the accuracy of the measurement. 2.5 Tidal volume requirements
2.5.1 Deaerated distilled water should be used as the measuring liquid. To deaerate distilled water, the water should be placed under a reduced pressure condition of less than 4000Pa (30mmHg) for 3 hours, and then stored under low pressure for 3 hours before use, or the water should be boiled for 15 minutes at atmospheric pressure for deaeration. During the measurement process, try to avoid air from dissolving in the water again, and deaeration should be performed at least once every 12 hours, unless a special storage method is used.
2.5.2 The water temperature should be maintained at 23±3℃ during measurement. 2.5.3 In order to prevent the influence of ambient air convection on the measurement, an airflow shield should be added outside the measuring device. 2.5.4 The radiating surface of the ultrasonic transducer in the measuring fish should be directly coupled with the liquid to avoid errors caused by the additional coupling layer. Before measurement, the transducer surface, target and film should be cleaned and soaked in deaerated water for at least 2 hours. All bubbles on the surface should be removed during measurement.
2.5.5 The ultrasonic transducer should be installed in the measurement so that the axis of the ultrasonic beam it radiates is in a straight line with the axis of the target. 2.5.6 The distance between the transducer and the target and the film should be as small as possible to ensure that the measurement is carried out in the near field and avoid the influence of ultrasonic beam dispersion on the measurement. At the same time, it should not be too close to ensure that the sound energy reflected from the target surface is not directly reflected to the surface of the supersonic transducer. 2.6 Measurement uncertainty
For the device that meets the above requirements, when the accidental error is not greater than 1%, the measurement uncertainty of the ultrasonic power is not greater than 5%. 8 Secondary standard measurement equipment
3.1 Milliwatt measurement device
8.1.1 Device composition
The milliwatt measurement device uses the radiation pressure method to measure ultrasonic sound power. The device consists of a total reflection target, a force balance detection system and an indicator. The force balance detection system is used as a force measuring device, as shown in Figure 5. Figure 5 Schematic diagram of milliwatt-level secondary standard test device 1-zero detector, 2-reflection target, 3-acoustic transducer; 4-reflector: 5-service mechanism: 6-super-strict generator-indicator 3.1.2 Total reflection target
GB 7966-87
The structure, size, material and technical requirements of the total reflection target are in accordance with Article 2-4.1. You can also use an empty total reflection vehicle with a 45” reflection angle. 3.1.3 Measurement equipment
The resolution of the force measuring equipment in water should be better than that of No. 3. 3.1.4 Water scavenger
The requirements for the scavenging water are the same as those in Article 2.4.3. 3. 1.5 Transparent film
The requirements for transparent film are the same as those in 2.4.4. 3.1.6 Measurement uncertainty
For a device that meets the above requirements, the measurement uncertainty of the excess rate is not greater than 0. 3.2 Dead level measuring device
3.2.1 Radiation pressure method measurement device
3.2.1 Overview
The radiation pressure method generally uses standard depth radiation, catenary float acoustic radiometer and variometer acoustic radiometer. 3.2.1.2 Benchmark float and radiation meter
The benchmark float acoustic radiometer is composed of a pin-shaped reflector with a benchmark, as shown in Figure 6. The benchmark is immersed in a liquid (such as carbon dichloride) with a relative density greater than 1 and immiscible with water. The displacement of the floating float caused by the radiation is also measured to determine the overall sound generation rate. A
Figure 6 Benchmark type floating "acoustic radiation meter
1 Beyond the lack of energy 2-transparent membrane,-pan 4·Four models hungry: 5-except "water" B suction strict father span, 7·~ mobile beam GB 796687
3.2.1.3 chain floating sound radiation!
The floating system of the energy floating acoustic radiation meter consists of a root catenary hanging inside and a clamp-shaped skin emitter with a benchmark. The splash device is shown in Figure 7. The ultrasonic rate is determined by measuring the displacement of the floating "sinking" caused by the acoustic radiation force. Figure 7 Schematic diagram of the floating radiometer
1-wing tongue transducer, 2-transmissive membrane, 3-floating 4-ruler 5-slit, 6-suction tip, 7-degassing lift 3.2.1.4 Strain gauge The strain gauge acoustic radiometer consists of a total reflection target, a metal cantilever with a resistance strain gauge bridge and a static resistance strain gauge, as shown in Figure 8. The strain of the suspension caused by the radiation source is measured to determine the power. GB7966-87
Figure 8 Schematic diagram of the strain gauge acoustic radiometer
[-static resistance: 2-transmitter 3-ultrasonic transducer: 4-reflection gauge
5-piece inflammation, 1. The structure, size, material and technical requirements of the total reflection target are the same as those in Section 2.4.1. 3.2.1.6 Force measuring equipment
The force measuring resolution of the force measuring equipment shall not exceed F1mg, and the accuracy shall be greater than ±3%. 3.2.1.7 The requirements for water tanks are the same as those in Section 2.4.3. 3.2.1.8 The requirements for sound-transmitting membranes are the same as those in Section 2.4.4. 3.2.1.9 Measurement accuracy
For devices that meet the above requirements, the uncertainty of ultrasonic sound power measurement shall not exceed 10%. 3.2.2 Acousto-optic measurement device
3.2.2.1 Measurement principle
The phase light generated by a small-amplitude surface wave in a transparent liquid and the intensity of the first-order diffracted light generated by modulating the monochromatic light orthogonal to it is proportional to the square of the m-th order Bessel function of the Raman-Nath parameter √. Required (). , is the direct light without light modulation. Therefore, after determining the relative change value of each level of diffraction light intensity, the corresponding I value can be obtained from the Bayer function table, and the corresponding cross-sectional plane of the figure can be calculated using formula (3): W
32± (n- 1)2
-density of transparent liquid, kg/m\;
-ultrasonic propagation speed of transparent liquid, m/s:
light wavelength in vacuum, m,
-light refraction coefficient of transparent body.
method, ① surface wave hypothetical conditions are the same as those in Note 2.1, and the modification of sound absorption is the same as that in Note 2.1. 3.2.2.2 Measuring device
GB 7966-81
The measuring device consists of the collimated optical path of monochromatic light beam, transparent anechoic water model and diffracted light detection system, as shown in Figure 9. 9 optical measurement device
! User! Optical selector or optics, 2--straight light source: 3--converter--2-heart generator; 5--transparent H water, 6--long focal length lens, 8--digital display lens, 9--evaporation water 3.2., 2, 3 half-grid requirements
optical components point accuracy requirements price shift better than 0.02mm, angle accuracy better than ±1. The angle of the device is less than o.o1rad.
3. 2.2.4 The instrument should have two rotation degrees and one displacement degree adjustment capability to ensure that the acoustic beam axis is perpendicular to the beam axis. The displacement accuracy should be better than ±0.02mm and the angle accuracy should be better than ±1. 3.2.2.5 The beam should pass through an optically transparent half surface, parallel to each other, with an inclination angle of no more than 1. The requirements for the acoustic beam are the same as those in Section 2.4.3. 3.2.2.6 Measurement uncertainty
For devices that meet the above requirements, the measurement uncertainty of the acoustic power is not greater than +10%. For transducers with uneven radiation, only the output power is measured in the direction of the beam diameter, which may cause large errors. In this case, the measurement should be carried out around the axis with an equal/relatively high efficiency device (which should be greater than or equal to 4). The final value of the average value obtained is the power of the transducer.1 Device composition
The milliwatt-level measuring device uses the radiation pressure method to measure ultrasonic sound power. The device consists of a total reflection target, a force balance detection system and an indicator. The force balance detection system is used as a force measuring device, as shown in Figure 5. Figure 5 Schematic diagram of the milliwatt-level secondary standard measuring device 1-zero detector, 2-reflection target, 3-acoustic transducer; 4-reflector: 5-service mechanism: 6-ultrasonic generator-indicator 3.1.2 Total reflection target
GB 7966-87
The structure, size, material and technical requirements of the total reflection target are in accordance with Article 2-4.1. An air total reflection vehicle with a 45" reflection angle can also be used. 3.1.3 Measurement equipment
The resolution of the force measuring equipment in water should be better than that of No. 3. 3.1.4 Water scavenger
The requirements for the anechoic water scavenger are the same as those in Article 2.4.3. 3. 1.5 Transparent film
The requirements for transparent film are the same as those in 2.4.4. 3.1.6 Measurement uncertainty
For a device that meets the above requirements, the measurement uncertainty of the excess rate is not greater than 0. 3.2 Dead level measuring device
3.2.1 Radiation pressure method measurement device
3.2.1 Overview
The radiation pressure method generally uses standard depth radiation, catenary float acoustic radiometer and variometer acoustic radiometer. 3.2.1.2 Benchmark float and radiation meter
The benchmark float acoustic radiometer is composed of a pin-shaped reflector with a benchmark, as shown in Figure 6. The benchmark is immersed in a liquid (such as carbon dichloride) with a relative density greater than 1 and immiscible with water. The displacement of the floating float caused by the radiation is also measured to determine the overall sound generation rate. A
Figure 6 Benchmark type floating "acoustic radiation meter
1 Beyond the lack of energy 2-transparent membrane,-pan 4·Four models hungry: 5-except "water" B suction strict father span, 7·~ mobile beam GB 796687
3.2.1.3 chain floating sound radiation!
The floating system of the energy floating acoustic radiation meter consists of a root catenary hanging inside and a clamp-shaped skin emitter with a benchmark. The splash device is shown in Figure 7. The ultrasonic rate is determined by measuring the displacement of the floating "sinking" caused by the acoustic radiation force. Figure 7 Schematic diagram of the floating radiometer
1-wing tongue transducer, 2-transmissive membrane, 3-floating 4-ruler 5-slit, 6-suction tip, 7-degassing lift 3.2.1.4 Strain gauge The strain gauge acoustic radiometer consists of a total reflection target, a metal cantilever with a resistance strain gauge bridge and a static resistance strain gauge, as shown in Figure 8. The strain of the suspension caused by the radiation source is measured to determine the power. GB7966-87
Figure 8 Schematic diagram of the strain gauge acoustic radiometer
[-static resistance: 2-transmitter 3-ultrasonic transducer: 4-reflection gauge
5-piece inflammation, 1. The structure, size, material and technical requirements of the total reflection target are the same as those in Section 2.4.1. 3.2.1.6 Force measuring equipment
The force measuring resolution of the force measuring equipment shall not exceed F1mg, and the accuracy shall be greater than ±3%. 3.2.1.7 The requirements for water tanks are the same as those in Section 2.4.3. 3.2.1.8 The requirements for sound-transmitting membranes are the same as those in Section 2.4.4. 3.2.1.9 Measurement accuracy
For devices that meet the above requirements, the uncertainty of ultrasonic sound power measurement shall not exceed 10%. 3.2.2 Acousto-optic measurement device
3.2.2.1 Measurement principle
The phase light generated by a small-amplitude surface wave in a transparent liquid and the intensity of the first-order diffracted light generated by modulating the monochromatic light orthogonal to it is proportional to the square of the m-th order Bessel function of the Raman-Nath parameter √. Required (). , is the direct light without light modulation. Therefore, after determining the relative change value of each level of diffraction light intensity, the corresponding I value can be obtained from the Bayer function table, and the corresponding figure cross section flat beam acoustic power can be calculated using formula (3): Wbzxz.net
32± (n- 1)2
-density of transparent liquid, kg/m\;
-ultrasonic propagation speed of transparent liquid, m/s:
light wavelength in vacuum, m,
-light refraction coefficient of transparent body.
method, ① surface wave hypothetical conditions are the same as those in Note 2.1, and the modification of sound absorption is the same as that in Note 2.1. 3.2.2.2 Measuring device
GB 7966-81
The measuring device consists of the collimated optical path of monochromatic light beam, transparent anechoic water model and diffracted light detection system, as shown in Figure 9. 9 optical measurement device
! User! Optical selector or optics, 2--straight light source: 3--converter--2-heart generator; 5--transparent H water, 6--long focal length lens, 8--digital display lens, 9--evaporation water 3.2., 2, 3 half-grid requirements
optical components point accuracy requirements price shift better than 0.02mm, angle accuracy better than ±1. The angle of the device is less than o.o1rad.
3. 2.2.4 The instrument should have two rotation degrees and one displacement degree adjustment capability to ensure that the acoustic beam axis is perpendicular to the beam axis. The displacement accuracy should be better than ±0.02mm and the angle accuracy should be better than ±1. 3.2.2.5 The beam should pass through an optically transparent half surface, parallel to each other, with an inclination angle of no more than 1. The requirements for the acoustic beam are the same as those in Section 2.4.3. 3.2.2.6 Measurement uncertainty
For devices that meet the above requirements, the measurement uncertainty of the acoustic power is not greater than +10%. For transducers with uneven radiation, only the output power is measured in the direction of the beam diameter, which may cause large errors. In this case, the measurement should be carried out around the axis with an equal/relatively high efficiency device (which should be greater than or equal to 4). The final value of the average value obtained is the power of the transducer.1 Device composition
The milliwatt-level measuring device uses the radiation pressure method to measure ultrasonic sound power. The device consists of a total reflection target, a force balance detection system and an indicator. The force balance detection system is used as a force measuring device, as shown in Figure 5. Figure 5 Schematic diagram of the milliwatt-level secondary standard measuring device 1-zero detector, 2-reflection target, 3-acoustic transducer; 4-reflector: 5-service mechanism: 6-ultrasonic generator-indicator 3.1.2 Total reflection target
GB 7966-87
The structure, size, material and technical requirements of the total reflection target are in accordance with Article 2-4.1. An air total reflection vehicle with a 45" reflection angle can also be used. 3.1.3 Measurement equipment
The resolution of the force measuring equipment in water should be better than that of No. 3. 3.1.4 Water scavenger
The requirements for the anechoic water scavenger are the same as those in Article 2.4.3. 3. 1.5 Transparent film
The requirements for transparent film are the same as those in 2.4.4. 3.1.6 Measurement uncertainty
For a device that meets the above requirements, the measurement uncertainty of the excess rate is not greater than 0. 3.2 Dead level measuring device
3.2.1 Radiation pressure method measurement device
3.2.1 Overview
The radiation pressure method generally uses standard depth radiation, catenary float acoustic radiometer and variometer acoustic radiometer. 3.2.1.2 Benchmark float and radiation meter
The benchmark float acoustic radiometer is composed of a pin-shaped reflector with a benchmark, as shown in Figure 6. The benchmark is immersed in a liquid (such as carbon dichloride) with a relative density greater than 1 and immiscible with water. The displacement of the floating float caused by the radiation is also measured to determine the overall sound generation rate. A
Figure 6 Benchmark type floating "acoustic radiation meter
1 Beyond the lack of energy 2-transparent membrane,-pan 4·Four models hungry: 5-except "water" B suction strict father span, 7·~ mobile beam GB 796687
3.2.1.3 chain floating sound radiation!
The floating system of the energy floating acoustic radiation meter consists of a root catenary hanging inside and a clamp-shaped skin emitter with a benchmark. The splash device is shown in Figure 7. The ultrasonic rate is determined by measuring the displacement of the floating "sinking" caused by the acoustic radiation force. Figure 7 Schematic diagram of the floating radiometer
1-wing tongue transducer, 2-transmissive membrane, 3-floating 4-ruler 5-slit, 6-suction tip, 7-degassing lift 3.2.1.4 Strain gauge The strain gauge acoustic radiometer consists of a total reflection target, a metal cantilever with a resistance strain gauge bridge and a static resistance strain gauge, as shown in Figure 8. The strain of the suspension caused by the radiation source is measured to determine the power. GB7966-87
Figure 8 Schematic diagram of the strain gauge acoustic radiometer
[-static resistance: 2-transmitter 3-ultrasonic transducer: 4-reflection gauge
5-piece inflammation, 1. The structure, size, material and technical requirements of the total reflection target are the same as those in Section 2.4.1. 3.2.1.6 Force measuring equipment
The force measuring resolution of the force measuring equipment shall not exceed F1mg, and the accuracy shall be greater than ±3%. 3.2.1.7 The requirements for water tanks are the same as those in Section 2.4.3. 3.2.1.8 The requirements for sound-transmitting membranes are the same as those in Section 2.4.4. 3.2.1.9 Measurement accuracy
For devices that meet the above requirements, the uncertainty of ultrasonic sound power measurement shall not exceed 10%. 3.2.2 Acousto-optic measurement device
3.2.2.1 Measurement principle
The phase light generated by a small-amplitude surface wave in a transparent liquid and the intensity of the first-order diffracted light generated by modulating the monochromatic light orthogonal to it is proportional to the square of the m-th order Bessel function of the Raman-Nath parameter √. Required (). , is the direct light without light modulation. Therefore, after determining the relative change value of each level of diffraction light intensity, the corresponding I value can be obtained from the Bayer function table, and the corresponding cross-sectional plane of the figure can be calculated using formula (3): W
32± (n- 1)2
-density of transparent liquid, kg/m\;
-ultrasonic propagation speed of transparent liquid, m/s:
light wavelength in vacuum, m,
-light refraction coefficient of transparent body.
method, ① surface wave hypothetical conditions are the same as those in Note 2.1, and the modification of sound absorption is the same as that in Note 2.1. 3.2.2.2 Measuring device
GB 7966-81
The measuring device consists of the collimated optical path of monochromatic light beam, transparent anechoic water model and diffracted light detection system, as shown in Figure 9. 9 optical measurement device
! User! Optical selector or optics, 2--straight light source: 3--converter--2-heart generator; 5--transparent H water, 6--long focal length lens, 8--digital display lens, 9--evaporation water 3.2., 2, 3 half-grid requirements
optical components point accuracy requirements price shift better than 0.02mm, angle accuracy better than ±1. The angle of the device is less than o.o1rad.
3. 2.2.4 The instrument should have two rotation degrees and one displacement degree adjustment capability to ensure that the acoustic beam axis is perpendicular to the beam axis. The displacement accuracy should be better than ±0.02mm and the angle accuracy should be better than ±1. 3.2.2.5 The beam should pass through an optically transparent half surface, parallel to each other, with an inclination angle of no more than 1. The requirements for the acoustic beam are the same as those in Section 2.4.3. 3.2.2.6 Measurement uncertainty
For devices that meet the above requirements, the measurement uncertainty of the acoustic power is not greater than +10%. For transducers with uneven radiation, only the output power is measured in the direction of the beam diameter, which may cause large errors. In this case, the measurement should be carried out around the axis with an equal/relatively high efficiency device (which should be greater than or equal to 4). The final value of the average value obtained is the power of the transducer.1. 3.2.1.6 Force measuring equipment
The force measuring resolution of the force measuring equipment shall not exceed F1mg, and the accuracy shall be greater than ±3%. 3.2.1.7 The requirements for water tanks are the same as those in 2.4.3. 3.2.1.8 Sound-transmitting membranes
The requirements for sound-transmitting membranes are the same as those in 2.4.4. 3.2.1.9 Measurement accuracy
For devices that meet the above requirements, the minimum uncertainty of ultrasonic sound power measurement shall not exceed 10%. 3.2.2 Acousto-optic measurement device
3.2.2.1 Measurement principle
The phase light generated by a small-amplitude surface wave in a transparent liquid and the intensity of the first-order diffracted light generated by modulating the monochromatic light orthogonal to it is proportional to the square of the m-th order Bessel function of the Raman-Nath parameter √. "Required (). , is the direct light without optical modulation. Therefore, after measuring the relative change value of each diffracted light intensity, the corresponding I value can be obtained from the Bayer function table, and the acoustic power of the corresponding cross-section of the figure can be calculated using formula (3): W
32± (n- 1)2
-density of transparent liquid, kg/m\;
-ultrasonic propagation speed of transparent liquid, m/s:
light wavelength in vacuum, m,
-light refraction coefficient of transparent body.
method, ① the surface wave assumption condition is the same as the requirements of note 2.1, and the modification of acoustic absorption is the same as the notes of note 2.1. 3.2.2.2 Measuring device
GB 7966-81
The measuring device consists of a monochromatic beam collimating optical path, a transparent anechoic water model and a diffraction light detection system, as shown in Figure 9. 9 Optical measuring device
! User! Optical selector or optics, 2--straight light source: 3--converter--2-heart generator; 5--transparent anechoic water model, 6--long focal length lens, a digital display lens, 8--photoelectric detector, 9--evaporation water 3.2., 2, 3 Half-grid requirements
The accuracy of the point deviation of the optical components is better than ±0.02mm, and the angle accuracy is better than ±1. The angle of the device is less than o.o1rad.
3. 2.2.4 The instrument should have two rotation degrees and one displacement degree adjustment capability to ensure that the acoustic beam axis is perpendicular to the beam axis. The displacement accuracy should be better than ±0.02mm and the angle accuracy should be better than ±1. 3.2.2.5 The beam should pass through an optically transparent half surface, parallel to each other, with an inclination angle of no more than 1. The requirements for the acoustic beam are the same as those in Section 2.4.3. 3.2.2.6 Measurement uncertainty
For devices that meet the above requirements, the measurement uncertainty of the acoustic power is not greater than +10%. For transducers with uneven radiation, only the output power is measured in the direction of the beam diameter, which may cause large errors. In this case, the measurement should be carried out around the axis with an equal/relatively high efficiency device (which should be greater than or equal to 4). The final value of the average value obtained is the power of the transducer.1. 3.2.1.6 Force measuring equipment
The force measuring resolution of the force measuring equipment shall not exceed F1mg, and the accuracy shall be greater than ±3%. 3.2.1.7 The requirements for water tanks are the same as those in 2.4.3. 3.2.1.8 Sound-transmitting membranes
The requirements for sound-transmitting membranes are the same as those in 2.4.4. 3.2.1.9 Measurement accuracy
For devices that meet the above requirements, the minimum uncertainty of ultrasonic sound power measurement shall not exceed 10%. 3.2.2 Acousto-optic measurement device
3.2.2.1 Measurement principle
The phase light generated by a small-amplitude surface wave in a transparent liquid and the intensity of the first-order diffracted light generated by modulating the monochromatic light orthogonal to it is proportional to the square of the m-th order Bessel function of the Raman-Nath parameter √. "Required (). , is the direct light without optical modulation. Therefore, after measuring the relative change value of each diffracted light intensity, the corresponding I value can be obtained from the Bayer function table, and the acoustic power of the corresponding cross-section of the figure can be calculated using formula (3): W
32± (n- 1)2
-density of transparent liquid, kg/m\;
-ultrasonic propagation speed of transparent liquid, m/s:
light wavelength in vacuum, m,
-light refraction coefficient of transparent body.
method, ① the surface wave assumption condition is the same as the requirements of note 2.1, and the modification of acoustic absorption is the same as the notes of note 2.1. 3.2.2.2 Measuring device
GB 7966-81
The measuring device consists of a monochromatic beam collimating optical path, a transparent anechoic water model and a diffraction light detection system, as shown in Figure 9. 9 Optical measuring device
! User! Optical selector or optics, 2--straight light source: 3--converter--2-heart generator; 5--transparent anechoic water model, 6--long focal length lens, a digital display lens, 8--photoelectric detector, 9--evaporation water 3.2., 2, 3 Half-grid requirements
The accuracy of the point deviation of the optical components is better than ±0.02mm, and the angle accuracy is better than ±1. The angle of the device is less than o.o1rad.
3. 2.2.4 The instrument should have two rotation degrees and one displacement degree adjustment capability to ensure that the acoustic beam axis is perpendicular to the beam axis. The displacement accuracy should be better than ±0.02mm and the angle accuracy should be better than ±1. 3.2.2.5 The beam should pass through an optically transparent half surface, parallel to each other, with an inclination angle of no more than 1. The requirements for the acoustic beam are the same as those in Section 2.4.3. 3.2.2.6 Measurement uncertainty
For devices that meet the above requirements, the measurement uncertainty of the acoustic power is not greater than +10%. For transducers with uneven radiation, only the output power is measured in the direction of the beam diameter, which may cause large errors. In this case, the measurement should be carried out around the axis with an equal/relatively high efficiency device (which should be greater than or equal to 4). The final value of the average value obtained is the power of the transducer.
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