Some standard content:
GB/T 15951
This standard is formulated based on the second edition of the International Electrotechnical Commission standard IEC 373 "Mechanical coupler farmeasurcments on bone vibratora199o-o1". As this international standard is technically mature and widely promoted internationally, it plays a driving role in ensuring the uniformity of hearing values in my country, so it is adopted as an equivalent to adapt to the needs of international trade, technical and economic exchanges and the adoption of international standards as soon as possible. Appendix A and Appendix B of this standard are both informative appendices. This standard was proposed by the Chinese Academy of Computer Science and Technology and issued by the Chinese Academy of Metrology. The drafting unit of this standard is the Chinese Academy of Computer Science and Technology. The main drafters of this standard are: Zhang Jucai, Shen Yang, GB/T 15951—1995
IEC Foreword
1) Formal decisions or agreements on IEC technical documents prepared by technical committees in which all national committees having a special interest in the subject are represented express, as far as possible, international consensus on the subject matter involved. 2) They are used internationally only in the form of international recommendations and are accepted by national committees for this purpose. 3) In order to promote international unification, the IEC hopes that all national committees will adopt the texts recommended by the IEC as their national regulations, as far as national conditions permit. Any deviation between IEC recommendations and corresponding national regulations should be clearly stated in the latter as far as possible. 4) The IEC has not established any procedures for indicating type approval markings, so the IEC optical authority requires that the items of equipment conform to those in the recommended text.
This standard was provided by IEC Technical Committee No. 29, "Electroacoustics". This standard replaces the first edition issued in 1971. The text of this standard is based on the following documents:
Six-month method
200(00)50
Voting report
29C(CO)54
One-month method
29C(CO)58
Full information on the voting for the approval of this standard can be found in the voting report shown in the table above. The following reference is used in this standard:
Voting report
29600)61
IEC 118-9(1985), Hearing aids
Part 9: Methods of measurement of characteristics of hearing aids with bone conduction output 1EC 645(1979): Audiometer
150)266(1975); Acoustics - Frequencies commonly used in acoustic measurementsIS07566(1987): Acoustics - Standard reference class 1 range for calibration of pure tone bone conduction audiometers
National Standard of the People's Republic of China
Mechanical coupler for meagurementson bone vibrators
GB/T 15951
idtIEC373:1990
This standard specifies the requirements for mechanical couplers, which are used for calibrating bone conduction audiometers, measuring bone vibrators (bone conduction headphones) and measuring bone conduction hearing aids in the frequency range of 125Hz to 8000Hz. 1.1 Audiometry
This standard is used for audiometry. Its purpose is to provide a calibration method for bone vibrators used for bone conduction audiometry by specifying the force impedance loaded on the vibrator standard and the device for measuring the alternating force generated. GB11669 specifies the reference equivalent hearing threshold force level corresponding to normal hearing. For this purpose, according to the provisions in GB7341, the bone conduction vibrator is required to have a flat top with an area of 17525mm. And a static force of 5.5N0.5N is applied to the force coupler. The force coupler can also be used for hearing to measure the frequency response of the bone vibrator, unwanted sound radiation, harmonic distortion and other measurements.
1.2 Hearing aids
The purpose of this standard for hearing aids is to measure the electromechanical characteristics of bone vibrators used in hearing aids (sensitivity, frequency response, harmonic distortion, etc.); when the entire bone conduction hearing aid is dynamically loaded with a specified impedance and a static force in the range of 1.7N to 4N is added, the acoustic-mechanical characteristics of the entire bone conduction hearing aid are measured.
2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. The versions shown are valid at the time of publication of this standard. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB324080 Common questions in acoustic measurement G3 7341-87 Audiometer
CB1166989 Standard for acoustic calibration of pure tone bone conduction audiometers, zero level IEC118-9 (1985) Hearing aids Part 9: Methods for measuring the characteristics of hearing aids with bone conduction headphone output 3 Definitions
This standard adopts the following definitions,
3.1 Bonevibrator
An electromechanical transducer that produces hearing by vibrating the skull. 3.2 Merhanical coupler A device that provides a specified force impedance to a bone vibrator with a specified static force applied thereto, and is equipped with an electromechanical transducer that determines the alternating force level between the vibrator and the contact surface of the force coupler.
3.3 Alternating farce level, (farce level) The ratio of the effective value of the force transmitting vibration to the reference value of 1 micronewton (1mV) is the logarithm with the base 10 multiplied by 20. Unit: B, approved by the State Bureau of Technical Supervision on December 21, 1995, and implemented on August 1, 1996.
GB/T15951—1995
3.4 Mechanical impedance of a sinusoidally vibrating object with a specific frequency mechanical impedance of a sinusoidally vibrating object with a specific frequency
The alternating force transmitting vibration divided by the complex quotient of the velocity component of the object in the small direction of action, unit: Ns?Ⅱ-13.5 Trierhanical impedance level The ratio of the absolute value (modulus) of the knife impedance to the reference value 1N8·m is the logarithm with the base 10 multiplied by 20. Unit: dB, 3.6 Mechanical resistance (complex number) The real part of mechanical impedance.
3.7 Mechanical reactance
(complex number) The imaginary part of mechanical impedance.
Note: The mechanical reactance caused by inertia is usually marked as positive. 3.8 Sensitivity level
The ratio of the sensitivity of the force coupler to the reference sensitivity 1V/N is the logarithm with the base 10 multiplied by 20. Sensitivity is defined as the electrical output in volts when an alternating force in Newtons is applied. Unit: dB. 4 Design features and specifications
4.1 Overview
The force coupler should consist of a rigid mass of approximately 3.5 kg with a built-in force-sensitive element. The small sensitive element is covered with a viscoelastic material of the shape specified in 4.4. For uniaxial vibrations coincident with the principal axis of symmetry of the force coupler, the force impedance of the assembly shall comply with the requirements of 4.2 and 4.3. When the natural vibration frequency of the support is not more than 1-12.5 Hz, the entire assembly shall be able to withstand a static force of up to 6 N (including the weight of the vibrator under test if mounted on a vertical axis).
1. It is recommended to include a temperature sensitive device in close contact with the mass of the coupling device to allow correct measurement of temperature during use and calibration (see 5.3). 2 Appendix A (informative appendix) gives examples of force couplers that comply with this standard. 4.2 Force impedance
When the coupler is driven by a vibrator having a flat circular neck with an area of 175 mm and a static force of 5.4 N, it shall provide the force impedance levels and tolerances specified in Table 1 at 23°C. The static force includes the weight of the vibrator and any unsupported parts of the force transducer (when mounted on its vertical axis).
Force impedance level
(reference: 1N-s*n 1)
GB/T15951...1995
Table 1 (end)
Force impedance level
(reference: 1N-g\m-\)
*These frequencies are used for audiometry, but are included in the preferred series specified in GB 3240. Note
1The values of force impedance level and tolerance are obtained from the experimental data of a few force couplers. Under similar conditions, when the static force is reduced to 2.5 N, the force impedance level at 250 Hz should be 2±0.? dB lower than the force required resistance level measured when the static force is 5.4 N. 2 This has become a specification. It is not recommended to use lower static values when testing specific devices. 4.3 Phase angle of force impedance
When the same conditions as specified in 4.2 are used with a static force of 5.When driven with 4N, the phase angle of the force impedance of the force coupler at a frequency of 250Hz and a temperature of 23℃ should be -63°±4″.
4.4 External geometry
In the non-deformed state, the contact surface of the force coupler should be a spherical surface with a nominal radius of 96mm. The exposed part of the spherical surface should be a circle with a minimum diameter of 35mm. Within this diameter, the surface should be smooth, or the tolerance of the radius of the shape is ±15mm. Outside this diameter, the external contour of the force coupler should be avoided from being affected by any test bone vibrator. 4.5 Attachment of vibrator
Provides a device for applying the required static force to the test vibrator such as on the force coupler. The device should be able to calibrate the vibrator on the head ring or the vibration isolation vibrator without causing false responses of the vibrator. Note
1 It is recommended to use elastic bands symmetrically applied to the back of the vibrator to make the vibration on the force coupler The force mechanism (such as a spring or gravity load mechanism) is coupled to the vibrator under test. The stiffness of the elastic band in the vibration force direction should be negligible. 2 For the measurement of the head ring vibrator, it is recommended that there should be a method of stretching the head ring to produce the required static force. The empty end of the head ring should be pressed on the elastic material to reduce the false resonance effect. The head ring should not affect the elasticity of the elastic coupling. An example of a mounting method is shown in Figure A2 of IEC118-9 Annex A (indicative annex).
3 A method should be provided to position the vibrator symmetrically on the coupling. 5 Calibration
5.1 Sensitivity level
The force coupler should be calibrated by the manufacturer at a sensitivity level of 23°C ± 1°C at the frequencies listed in Table 1. The alternating force should be applied through a 175mm flat-top circular excitation surface, and the sensitivity level should be given for a coupling force of 5.4N and 2.5N. The electrical load should be stated.
Each force coupler shall be provided with a table or diagram of calibration values and a statement of defined uncertainty. The uncertainty of calibration shall not exceed 1.0 dB for frequencies up to 2 kHz and 2.0 dB for frequencies up to 8 kHz. Note
When applying alternating force measurements, it is usually necessary to compensate for the mass of the drive tip material between the calibrated force sensor and the outer surface of the force coupler. The manufacturer's instructions for the transducer shall be included.
GB/T15951—1995
2 For calibrations where temperature is specified elsewhere in this standard, it shall be assumed that the temperature refers to the temperature of the force coupler. Due to the large mass heat capacity including the device block, it may take several hours to achieve thermal equilibrium. It is not appropriate to rely on measurements at room temperature. 5.2 Impedance Level
The manufacturer shall provide a table or graph of values for each force coupler, showing the results of the force impedance level measurements at the frequencies listed in Table 1 at 23°C ± 1°C under the conditions specified in 4.2.
5.3 Temperature Dependence
As a type test requirement, the measurements in 5.1 and 5.2 shall be carried out at least within a temperature range of 18°C to 28°C, characterizing the temperature dependence of the sensitivity and the force impedance level at a sufficient number of frequencies. This information shall be provided in the form of temperature coefficients valid for the temperature range stated. Note: These data represent only the temperature dependence. These values representing the temperature dependence cannot usually be used to correct data at other temperatures to the data at the reference temperature of 23°C, because the effect of changes in the impedance level on the alternating force output of the measured vibrator is unknown. 6 Marking and Instructions
6.1 Marking of Force Couplers
Force couplers conforming to this standard shall be marked with the manufacturer's name or trademark, serial number and reference number. 6.2 Instructions
The force coupler shall be provided with instructions which shall contain at least the information required in Clause 5. In addition, the instructions shall include:
a) detailed instructions to be followed to ensure that the force coupler meets the requirements of this standard; b) detailed recommended calibration procedures;
c) temperature and humidity limits that may cause permanent damage to the force coupler. A1 Force impedance element
A1.1 Viscous screening components
a) Butyl pad
GB/T15951—1995
Appendix A
(Suggestive Appendix)
Example of a specific structure of a force coupler
The butyl pad (Figure A3) is a flat plate with a point diameter of approximately 40 mm to 50 mm and a thickness of 3.8 mm. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disodium
Mercaptobenzothiazole monosulfide
Must be mixed within 60 °C.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm5 Attachment of the vibrator
A device should be provided to apply the required static force to the vibrator under test such as on a force coupler. The device should be able to calibrate the vibrator on the head ring or an isolating vibrator that does not cause false responses of the vibrator. Note
1 It is recommended to use an elastic band symmetrically added to the back of the vibrator so that the force-generating mechanism (such as a spring or a gravity load mechanism) on the force coupler is closely coupled to the vibrator under test. The stiffness of the elastic band in the vibration force direction should be negligible. 2 For the measurement of the head ring type vibrator, it is recommended that there should be a method of stretching the head ring to produce the required static force. The empty end of the head ring should be pressed on an elastic material to reduce the false resonance effect. The head ring should not affect the elasticity of the elastic coupling. An example of a mounting method is shown in Figure A2 of IEC118-9 Annex A (indicative appendix).
3 A method should be provided to position the vibrator symmetrically on the force coupler. 5 Calibration
5.1 Sensitivity Levels
The force coupler shall be calibrated by the manufacturer at the sensitivity levels listed in Table 1 at 23°C ± 1°C. The alternating force shall be applied through a 175 mm flat-top circular excitation surface and the sensitivity levels shall be given for coupling forces of 5.4 N and 2.5 N. The electrical load shall be stated.
A table or diagram of calibration values shall be provided for each force coupler, together with a statement of defined uncertainty. The uncertainty of calibration shall not exceed 1.0 dB for frequencies up to 2 kHz and 2.0 dB for frequencies up to 8 kHz. Note
When applying alternating force measurements, it is usually necessary to compensate for the mass of the drive tip material between the calibrated force sensor and the outer surface of the force coupler. The manufacturer's statement of the transducer shall be included.
GB/T15951—1995
2 For calibrations where the temperature is specified elsewhere in this standard, the temperature shall be considered to refer to the temperature of the coupler. Due to the large mass heat capacity including the device block, it may take several hours to achieve thermal equilibrium, and it is not appropriate to rely on measurements at room temperature. 5.2 Impedance level
The manufacturer shall provide a numerical table or graph for each coupler, showing the results of the impedance level measurement at 23°C±1°C for the frequencies listed in Table 1 under the conditions specified in 4.2.
5.3 Temperature dependence
As a type test requirement, the measurements in 5.1 and 5.2 shall be carried out at least in the temperature range of 18°C to 28°C, and the temperature dependence of the sensitivity and impedance level shall be characterized at a sufficient number of frequency points. This information shall be provided in the form of temperature coefficients valid for the temperature range stated. Note: These data only represent the temperature dependence. These values indicating temperature dependence cannot normally be used to correct data at other temperatures to the data at the reference temperature of 23°C, because the effect of changes in impedance level on the alternating force output of the bone vibrator under test is unknown. 6 Marking and instructions
6.1 Marking of force couplers
Force couplers in accordance with this standard shall be marked with the manufacturer's name or trademark, serial number and this reference number. 6.2 Instructions
Force couplers shall be provided with instructions, which shall contain at least the information required in Chapter 5. In addition, they shall include,
a) detailed instructions to be followed to ensure that the coupler meets the requirements of this standard; b) detailed recommended calibration procedures;
c) temperature and humidity limits that may cause permanent damage to the force coupler. A1 Force impedance element
A1.1 Viscous screening components
a) Butyl pad
GB/T15951—1995
Appendix A
(Suggested Appendix)
Specific structure example of force coupling
The butyl pad (Figure A3) is a flat plate with a point diameter of about 40mm~~50mm and a thickness of 3.8mm. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal carbon black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disulfide
Mercaptobenzothiazole monosulfide
Must be mixed within 60℃.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm5 Attachment of the vibrator
A device should be provided to apply the required static force to the vibrator under test such as on a force coupler. The device should be able to calibrate the vibrator on the head ring or an isolating vibrator that does not cause false responses of the vibrator. Note
1 It is recommended to use an elastic band symmetrically added to the back of the vibrator so that the force-generating mechanism (such as a spring or a gravity load mechanism) on the force coupler is closely coupled to the vibrator under test. The stiffness of the elastic band in the vibration force direction should be negligible. 2 For the measurement of the head ring type vibrator, it is recommended that there should be a method of stretching the head ring to produce the required static force. The empty end of the head ring should be pressed on an elastic material to reduce the false resonance effect. The head ring should not affect the elasticity of the elastic coupling. An example of a mounting method is shown in Figure A2 of IEC118-9 Annex A (indicative appendix).
3 A method should be provided to position the vibrator symmetrically on the force coupler. 5 Calibration
5.1 Sensitivity Levels
The force coupler shall be calibrated by the manufacturer at the sensitivity levels listed in Table 1 at 23°C ± 1°C. The alternating force shall be applied through a 175 mm flat-top circular excitation surface and the sensitivity levels shall be given for coupling forces of 5.4 N and 2.5 N. The electrical load shall be stated.
A table or diagram of calibration values shall be provided for each force coupler, together with a statement of defined uncertainty. The uncertainty of calibration shall not exceed 1.0 dB for frequencies up to 2 kHz and 2.0 dB for frequencies up to 8 kHz. Note
When applying alternating force measurements, it is usually necessary to compensate for the mass of the drive tip material between the calibrated force sensor and the outer surface of the force coupler. The manufacturer's statement of the transducer shall be included.
GB/T15951—1995
2 For calibrations where the temperature is specified elsewhere in this standard, the temperature shall be considered to refer to the temperature of the coupler. Due to the large mass heat capacity including the device block, it may take several hours to achieve thermal equilibrium, and it is not appropriate to rely on measurements at room temperature. 5.2 Impedance level
The manufacturer shall provide a numerical table or graph for each coupler, showing the results of the impedance level measurement at 23°C±1°C for the frequencies listed in Table 1 under the conditions specified in 4.2.
5.3 Temperature dependence
As a type test requirement, the measurements in 5.1 and 5.2 shall be carried out at least in the temperature range of 18°C to 28°C, and the temperature dependence of the sensitivity and impedance level shall be characterized at a sufficient number of frequency points. This information shall be provided in the form of temperature coefficients valid for the temperature range stated. Note: These data only represent the temperature dependence. These values indicating temperature dependence cannot normally be used to correct data at other temperatures to the data at the reference temperature of 23°C, because the effect of changes in impedance level on the alternating force output of the bone vibrator under test is unknown. 6 Marking and instructions
6.1 Marking of force couplers
Force couplers in accordance with this standard shall be marked with the manufacturer's name or trademark, serial number and this reference number. 6.2 Instructions
Force couplers shall be provided with instructions, which shall contain at least the information required in Chapter 5. In addition, they shall include,
a) detailed instructions to be followed to ensure that the coupler meets the requirements of this standard; b) detailed recommended calibration procedures;
c) temperature and humidity limits that may cause permanent damage to the force coupler. A1 Force impedance element
A1.1 Viscous screening components
a) Butyl pad
GB/T15951—1995
Appendix A
(Suggested Appendix)
Specific structure example of force coupling
The butyl pad (Figure A3) is a flat plate with a point diameter of about 40mm~~50mm and a thickness of 3.8mm. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal carbon black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disulfide
Mercaptobenzothiazole monosulfide
Must be mixed within 60℃.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm0dB, 8kHz and below calibration, the uncertainty should not exceed 2.0dB. Note
When applying alternating force measurement, it is usually necessary to compensate for the mass of the driving tip material between the calibrated force sensor and the outer surface of the force coupler, and the manufacturer's instructions for the transducer should be included.
GB/T15951-1995
2 For calibrations where the temperature is specified in this standard, the temperature should be considered to refer to the temperature of the force coupler. Due to the large mass heat capacity including the device block, it may take several hours to achieve thermal equilibrium. It is not appropriate to measure based on room temperature. 5.2 Force impedance level
The manufacturer should provide a numerical table or diagram for each force coupler, giving the results of the force impedance level measurement listed in Table 1 at a frequency of 23°C ± 1°C under the conditions specified in Article 4.2.
5.3 Temperature dependence
As a type test requirement, the measurements in 5.1 and 5.2 shall be carried out at least within a temperature range of 18°C to 28°C, characterizing the temperature dependence of the sensitivity and impedance level at a sufficient number of frequency points. This information shall be provided in the form of temperature coefficients valid for the temperature range stated. Note: These data only represent the temperature dependence. These values representing the temperature dependence cannot usually be used to correct data at other temperatures to the data at the reference temperature of 23°C, because the effect of changes in impedance level on the alternating force output of the measured vibrator is unknown. 6 Marking and instructions
6.1 Marking of force couplers
Force couplers in accordance with this standard shall be marked with the manufacturer's name or trademark, serial number and standard number. 6.2 Instructions
Force couplers shall be provided with instructions, which shall contain at least the information required in Chapter 5. In addition, it should include:
a) detailed instructions to be followed to ensure that the coupler meets the requirements of this standard; b) detailed recommended calibration procedures;
c) temperature and humidity limits that may cause permanent damage to the force coupler. A1 Force impedance element
A1.1 Viscous screening components
a) Butyl pad
GB/T15951—1995
Appendix A
(Suggestive Appendix)
Example of specific structure of force coupler
The butyl pad (Figure A3) is a flat plate with a point diameter of about 40mm~~50mm and a thickness of 3.8mm. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disulfide
Mercaptobenzothiazole monosulfide
Must be mixed within 60 °C.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm0dB, 8kHz and below calibration, the uncertainty should not exceed 2.0dB. Note
When applying alternating force measurement, it is usually necessary to compensate for the mass of the driving tip material between the calibrated force sensor and the outer surface of the force coupler, and the manufacturer's instructions for the transducer should be included.
GB/T15951-1995
2 For calibrations where the temperature is specified in this standard, the temperature should be considered to refer to the temperature of the force coupler. Due to the large mass heat capacity including the device block, it may take several hours to achieve thermal equilibrium. It is not appropriate to measure based on room temperature. 5.2 Force impedance level
The manufacturer should provide a numerical table or diagram for each force coupler, giving the results of the force impedance level measurement listed in Table 1 at a frequency of 23°C ± 1°C under the conditions specified in Article 4.2.
5.3 Temperature dependence
As a type test requirement, the measurements in 5.1 and 5.2 shall be carried out at least within a temperature range of 18°C to 28°C, characterizing the temperature dependence of the sensitivity and impedance level at a sufficient number of frequency points. This information shall be provided in the form of temperature coefficients valid for the temperature range stated. Note: These data only represent the temperature dependence. These values representing the temperature dependence cannot usually be used to correct data at other temperatures to the data at the reference temperature of 23°C, because the effect of changes in impedance level on the alternating force output of the measured vibrator is unknown. 6 Marking and instructions
6.1 Marking of force couplers
Force couplers in accordance with this standard shall be marked with the manufacturer's name or trademark, serial number and standard number. 6.2 Instructions
Force couplers shall be provided with instructions, which shall contain at least the information required in Chapter 5. In addition, it should include:
a) detailed instructions to be followed to ensure that the coupler meets the requirements of this standard; b) detailed recommended calibration procedures;
c) temperature and humidity limits that may cause permanent damage to the force coupler. A1 Force impedance element
A1.1 Viscous screening components
a) Butyl pad
GB/T15951—1995
Appendix A
(Suggestive Appendix)
Example of specific structure of force coupler
The butyl pad (Figure A3) is a flat plate with a point diameter of about 40mm~~50mm and a thickness of 3.8mm. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disulfide
Mercaptobenzothiazole monosulfide
Must be mixed within 60 °C.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm8mm plate. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disulfide
Mercaptobenzothiazole monosulfide
Must be mixed within 60°.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm8mm plate. The synthesis of butyl is as follows: Butyl 35SH
Medium thermal black
Zinc fluoride (lead-free)
Magnesium oxide
Tetramethylthiuram disulfide
Mercaptobenzothiazole monosulfide
Must be mixed within 60°.
bh) Neoprene pad
Weight to basis ratio
The neoprene pad (Figure A3) is a flat plate with a diameter of about 40tn~50mm and a thickness of 3.1mm. The synthesis of the neoprene is as follows: Neoprene 35SH
Neoprene S-40www.bzxz.net
Magnolia zinc
Stearic acid
Sulfur ethylene
Sulfurized paste
Aromatic hydrocarbons
Butyrate
Polyethylene
Must be mixed within 60 days.
A1.2 Metal parts
a) Force impedance element base
Weight to basis ratio
The base 1 is made of stainless steel and is vulcanized with an appropriate primer (Figure A1). Its upper surface is spherical with a radius of 89mm plus 0.5mm, without obvious machining marks or other defects. b) Load Insert
The load insert is a truncated cone with a thickness of 2.5 mm ± 0.05 mm, see Figure A2. The insert is precision cut from an alloy with a density of 17000 kg/m3.
A1.3 Assembly
The chloroprene rubber disc is vulcanized on the steel base at a pressure of 0.25 MPa and a temperature of 170°C for 20 min. The steel base after vulcanization is filled with chlorine CB/T 15951--1995
and tungsten blocks (Figure A2). The butyl disc is vulcanized at a pressure of 0.13 MPa and a temperature of 155°C for 20 min. A2 Assembly
The force impedance element is mounted on the brass body shown in Figure A3, and the piezoelectric sensitive element is sandwiched between them. RL.5
Unit: mm
Figure A1 Dimensions of force impedance element
Unit: mm
Figure A2 Dimensions of tungsten load plug-in
GB/115951-1995
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in
Tungsten load plug-in|| These values were derived by comparing data from the scientific literature published between 1954 and 1959. At that time, no practicality was found in specifying tolerances for the specification. Experience in manufacturing force couplers showed that the design objectives were difficult to achieve, especially since the frequency dependence of the force impedance did not strictly correspond to that of a physically realizable device. Based on this study, the current edition (the 1st edition) with wide-band tolerances was prepared on the basis of a number of mass-produced force couplers. The work of ISO TC 43 on the international standard for reference equivalent hearing valve force levels for normal hearing was based on force couplers in accordance with the current edition of IEC 373, which was the reason why ISO requested a revision of the first edition. Since 1959, further experimental work on the force impedance of the human skull has been published. This standard has been further revised to take these results into account. However, the basic view on the scientific basis of the artificial skull has been obtained recently. In order to meet the needs of users in the audiometry field and the hearing aid field, it is urgent to provide an improved solution for commercial devices (force couplers). Table B1 gives the force impedance level values calculated from the force resistance values and force resistance values specified in the first edition of IEC373 for reference. These values can be compared with the values in Table 1 of this standard.
# Values are rounded to the nearest 0.53.
Force Impedance Level
Test Nsm
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.