GB/T 43073-2023Pneumatic fluid power - Test methods for measuring acoustic emission pressure levels of exhaust silencers (English PDF)

3.1 emission sound pressure

p

sound pressure, at a specified position near a noise source, when the source is in operation under specified operating and mounting conditions on a reflecting plane surface, excluding the effects of background noise as well as the effects of reflections other than those from the plane or planes permitted for the purpose of the test

Note: Emission sound pressure is expressed in pascals (pa).

3.1 emission sound pressure

p

sound pressure, at a specified position near a noise source, when the source is in operation under specified operating and mounting conditions on a reflecting plane surface, excluding the effects of background noise as well as the effects of reflections other than those from the plane or planes permitted for the purpose of the test

Note: Emission sound pressure is expressed in pascals (pa).

3.2 emission sound pressure level

Lp

ten times the logarithm to the base 10 of the ratio of the square of the emission sound pressure, p, to the square of a reference value, p0

where the reference value, p0, is equal to 20µPa

Note: Emission sound pressure level is expressed in decibels (dB).

3.2 emission sound pressure level

Lp

ten times the logarithm to the base 10 of the ratio of the square of the emission sound pressure, p, to the square of a reference value, p0

where the reference value, p0, is equal to 20µPa

Note: Emission sound pressure level is expressed in decibels (dB).

3.3 measured equivalent continuous sound pressure level

Lp, T

ten times the logarithm to the base 10 of the ratio of the time average of the square of the emission sound pressure, p, during a stated time interval of duration, T (starting at t1 and ending at t2), to the square of a reference value, p0

where the reference value, p0, is equal to 20 µPa.

Note 1: Measured equivalent sound pressure level is expressed in decibels (dB).

Note 2: If specific frequency and time weightings as specified in IEC 61672-1 and/or specific frequency bands are applied, this is indicated by appropriate subscripts, e.g. LAeq denotes the A-weighted emission sound pressure level.

Note 3: The formula in 3.3 is equivalent to that for the environmental noise descriptor “equivalent continuous sound pressure level". However, the emission quantity defined above is used to characterize the noise emitted by a source under test and assumes that standardized measurement and operating conditions as well as a controlled acoustical environment are used for the measurements.

3.3 measured equivalent continuous sound pressure level

Lp, T

ten times the logarithm to the base 10 of the ratio of the time average of the square of the emission sound pressure, p, during a stated time interval of duration, T (starting at t1 and ending at t2), to the square of a reference value, p0

where the reference value, p0, is equal to 20 µPa.

Note 1: Measured equivalent sound pressure level is expressed in decibels (dB).

Note 2: If specific frequency and time weightings as specified in IEC 61672-1 and/or specific frequency bands are applied, this is indicated by appropriate subscripts, e.g. LAeq denotes the A-weighted emission sound pressure level.

Note 3: The formula in 3.3 is equivalent to that for the environmental noise descriptor “equivalent continuous sound pressure level". However, the emission quantity defined above is used to characterize the noise emitted by a source under test and assumes that standardized measurement and operating conditions as well as a controlled acoustical environment are used for the measurements.

3.4 frequency range of interest

sound levels determined for frequencies from 100 Hz to 20000 Hz

3.4 frequency range of interest

sound levels determined for frequencies from 100 Hz to 20000 Hz

3.5 background noise

noise from all sources other than the source under test

Note: Background noise can include contributions from airborne sound, noise from structure-borne vibration and electrical noise in instrumentation.

3.5 background noise

noise from all sources other than the source under test

Note: Background noise can include contributions from airborne sound, noise from structure-borne vibration and electrical noise in instrumentation.

3.6 background noise correction

K1A

correction applied to the measured sound pressure levels to account for the influence of background noise

3.6 background noise correction

K1A

correction applied to the measured sound pressure levels to account for the influence of background noise

3.7 environmental correction

K2A

term to account for the influence of reflected sound on the mean sound pressure level on the reference measurement surface

Note: Environmental correction is expressed in decibels (dB).

3.7 environmental correction

K2A

term to account for the influence of reflected sound on the mean sound pressure level on the reference measurement surface

Note: Environmental correction is expressed in decibels (dB).

5.1 Test bench

According to the test method chosen, the test bench shall be in accordance with ISO 6358-1 (steady- state mode) or ISO 6358-2 (discharge mode). In particular, the size of the upstream measurement tube shall be in accordance with ISO 6358-1 specifications.

Relevant for the comparison of the sound emission is the pressure and the flow rate (flow rate is in this case a functional value to ensure that the silencer fits to the application). Therefore, it is recommended to use the test bench from ISO 6358-1 if possible as the measured flow rate is based on a stable pressure. If that in ISO 6358-2 is chosen, the values of pressure and flow change significantly within the test due to the nature of the discharge method. Therefore, the value of the flow rate shows a wider tolerance range

5.1 Test bench

According to the test method chosen, the test bench shall be in accordance with ISO 6358-1 (steady- state mode) or ISO 6358-2 (discharge mode). In particular, the size of the upstream measurement tube shall be in accordance with ISO 6358-1 specifications.

Relevant for the comparison of the sound emission is the pressure and the flow rate (flow rate is in this case a functional value to ensure that the silencer fits to the application). Therefore, it is recommended to use the test bench from ISO 6358-1 if possible as the measured flow rate is based on a stable pressure. If that in ISO 6358-2 is chosen, the values of pressure and flow change significantly within the test due to the nature of the discharge method. Therefore, the value of the flow rate shows a wider tolerance range

5.2 Pneumatic pressure measurement

Only the pressure in the upstream pressure-measuring tube shall be measured. The set-up shall be in accordance with ISO 6358-1.

5.2 Pneumatic pressure measurement

Only the pressure in the upstream pressure-measuring tube shall be measured. The set-up shall be in accordance with ISO 6358-1.

5.3 Flow measurement

The flow during the sound pressure measurement shall be recorded. The test set-up shall be in accordance with ISO 6358-1.

Note: Correlative flow characteristic values are also recorded according to ISO 6358-1 or ISO 6358-2.

5.3 Flow measurement

The flow during the sound pressure measurement shall be recorded. The test set-up shall be in accordance with ISO 6358-1.

Note: Correlative flow characteristic values are also recorded according to ISO 6358-1 or ISO 6358-2.

5.4 Sound pressure measurement

5.4 Sound pressure measurement

5.4.1 General

The measurement of sound pressure can be done at one or three positions. Measurement at three positions increases the precision of the result and reduces the uncertainty of the measurement. Direct incident flow on microphones should be avoided, due to noise generation by the microphones.

5.4.1 General

The measurement of sound pressure can be done at one or three positions. Measurement at three positions increases the precision of the result and reduces the uncertainty of the measurement. Direct incident flow on microphones should be avoided, due to noise generation by the microphones.

5.4.2 Measurement at one position

In this case, sound pressure shall be measured at one point positioned at 60° from the axis of the measurement tube, at 1m from the centre of the end of the transition connector and at a height of 1 m, as shown in Figure 1.

5.4.2 Measurement at one position

In this case, sound pressure shall be measured at one point positioned at 60° from the axis of the measurement tube, at 1m from the centre of the end of the transition connector and at a height of 1 m, as shown in Figure 1.

5.4.3 Measurement at three positions

In this case, sound pressures shall be measured at three positions distributed around the arc of a circle 1m in radius and from the centre of the end of the pressure measurement tube and at a height of 1 m. The points shall be positioned at 15°, 60°and 105° from the axis of the tube, as shown in Figure 2.

color: rgb(153, 153, 153);

background-color: rgb(248, 248, 248);

border-bottom: 1px solid rgb(153, 153, 153);

GB/T 43073-2023 Pneumatic fluid power—Test methods for measuring acoustic emission pressure levels of exhaust silencers (English) Standard No.

Translation Price(USD) 375.0 Implemented on 2023-9-7 Delivery

via email in 1~3 business day

Add GB/T 43073-2023 to Cart

Detail of GB/T 43073-2023 Standard No.

Pneumatic fluid power—Test methods for measuring acoustic emission pressure levels of exhaust silencers Chinese Name 气动 测量排气消声器声压级的试验方法

Chinese Classification J20

Professional Classification GB ICS Classification Issued by SAMR; SAC Issued on 2023-9-7 Implemented on 2023-9-7 Status valid Superseded by Superseded on Abolished on Superseding Language English File Format PDF Word Count 12500 words

Translation Price(USD) 375.0 Keywords

GB/T 43073-2023, GB 43073-2023, GBT 43073-2023, GB/T43073-2023, GB/T 43073, GB/T43073, GB43073-2023, GB 43073, GB43073, GBT43073-2023, GBT 43073, GBT43073

Introduction of GB/T 43073-2023

Pneumatic fluid power - Test methods for measuring acoustic emission pressure levels of exhaust silencers

5.4.3 Measurement at three positions

In this case, sound pressures shall be measured at three positions distributed around the arc of a circle 1m in radius and from the centre of the end of the pressure measurement tube and at a height of 1 m. The points shall be positioned at 15°, 60°and 105° from the axis of the tube, as shown in Figure 2.