GB/T 23281-2009 English PDFUS$229.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 23281-2009: Metal forming machinery -- Noise measurement method of sound pressure levels Status: Valid
Basic dataStandard ID: GB/T 23281-2009 (GB/T23281-2009)Description (Translated English): Metal forming machinery -- Noise measurement method of sound pressure levels Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: J62 Classification of International Standard: 25.120.10 Word Count Estimation: 10,166 Date of Issue: 2009-03-16 Date of Implementation: 2009-11-01 Adopted Standard: ISO 11202-1995, NEQ Regulation (derived from): National Standard Approval Announcement 2009 No.2 (Total No.142) Issuing agency(ies): General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China Summary: This standard specifies the forging machinery noise level measuring instruments, test environment, measurement conditions, measurement methods. This standard applies to the measurement noise A-weighted sound pressure level by forging machinery operating position and the specified location in. GB/T 23281-2009: Metal forming machinery -- Noise measurement method of sound pressure levels---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.Metal forming machinery -- Noise measurement method of sound pressure levels ICS 25.120.10 J62 National Standards of People's Republic of China GB/T 23281-2009 Measurement method of noise sound pressure level of forging machinery (ISO 11202.1995, NEQ) Published on.2009-03-16 2009-11-01 Implementation General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Released by the Standardization Administration of China Measurement method of noise sound pressure level of forging machinery 1 ScopeThis standard specifies the measurement instruments, test environment, measurement conditions, measurement methods, etc. for the noise sound pressure level of forging machinery. This standard applies to the A-weighted measurement of noise sound pressure level at the operating position and specified position of the forging machinery.2 Normative referencesThe clauses in the following documents become clauses of this standard through reference in this standard. For dated references, all subsequent Amendments (excluding errata content) or revisions do not apply to this standard, however, parties to agreements based on this standard are encouraged to study Is the latest version of these files available. For undated references, the latest edition applies to this standard. GB/T 3102.7 Acoustic Quantities and Units (GB/T 3102.7-1993, eqv ISO 31-7.1992) GB/T 3785-1983 Electrical and acoustic properties and test methods of sound level meters GB/T 3947 Acoustic terminology GB/T 15173-1994 Sound Calibrator GB/T 17181-1997 Integral average sound level meter (idt IEC 60804.1985) GB/T 23282-2009 Measurement method for noise sound power level of forging machinery3 Terms and DefinitionsGB/T 3947 and GB/T 3102.7 established and the following terms and definitions apply to this standard. 3.1 Airborne sound is radiated by the sound source under test (the machine under test). Note. Noise emission characteristics can be listed on the product label or product manual. The basic noise emission characteristics are the sound power level of the sound source and the working position near the sound source. emission sound pressure levels at the location and other specified locations. 3.2 On a reflective plane, the sound pressure at a specified location near a forging machine operating under specified installation and operating conditions. it does not include the back Scenic noise and the influence of other acoustic reflections outside the emitting surface allowed by this measurement method, the unit is Pa. 3.3 Lp Variety. The emission sound pressure level shall be measured at the specified location, which shall comply with the test procedures. 3.4 The maximum transient value of the emission sound pressure level measured in one operating cycle, in dB. GB/T 23281-2009 3.5 The sound field in an isotropic homogeneous medium in the half-space above an infinite, hard surface where the machine under test is located. 3.6 The location designated for the operator near the machine under test. 3.7 Persons engaged in machine-related work tasks near the machine under test. 3.8 Machine-related locations, including but not limited to operator locations. The location can be a single fixed point, or several points on a path, or several points on the surface at a specified distance from the machine. If relevant test procedures are available, state them therein. 3.9 The time taken for the machine under test to complete a specified process. 3.10 The time required for the machine under test to complete a working cycle, in which each operating period occurs in a prescribed sequence, and each operating period is associated with a A specific process is linked, and the specific process may occur only once in a running cycle, or it may be repeated many times. 3.11 A continuous recording of the emission sound pressure level as a function of time is obtained during one or more operating periods of an operating period or operating cycle. 3.12 Noise from all sound sources other than the sound source under test. 3.13 The measured sound pressure level when the machine under test is not working, in dB. 3.14 K1 This correction value is used to represent the influence of background noise on the emission sound pressure level of the machine under test at the designated position. K1 is related to the frequency, and the unit is dB. A The correction term K1A in the weighted case is obtained from the A-weighted measurements. 3.15 K2 This correction value is used to express the influence of sound reflection or sound absorption on the surface sound pressure level, K2 is related to the frequency, and the unit is dB. Weighting in A In this case, it is represented by K2A. 3.16 This correction value is used to represent the influence of reflected sound on the emission sound pressure level of the machine under test at the designated position (eg working position), in dB. K3 and frequency and location. In the case of A-weighting, it is represented by K3A. GB/T 23281-2009 3.17 The distance from the specified location to the closest major sound source to the machine. If the main sound source of the machine cannot be determined, select from the specified location to the machine The distance of the nearest part is taken as h.4 Measuring instrumentsWhen measuring, use a type 1 sound level meter (indication accuracy ±0.7dB) and an integral sound level meter in accordance with the provisions of GB 3785-1983. The average sound level meter shall meet the requirements of type 1 or above integral average sound level meter specified in GB/T 17181. Before and after each measurement, an acoustic calibrator with an accuracy better than ±0.3dB (Class 1 accuracy specified in GB/T 15173-1994) should be used to measure the entire The measurement system is calibrated. The sound calibrator shall be inspected once a year in accordance with the requirements of GB/T 15173-1994.Every two years should be in accordance with the requirements of GB/T 3785-1983, Calibrate the instrument system at least once. The date of the last calibration to national standards should be recorded.5 Test environment5.1 Overview This standard applies to the environment in accordance with 5.2 and the background noise is corrected according to 5.3. 5.2 Applicable criteria for test environment The environmental correction value K2A of the test environment (as defined in GB/T 23282-2009 Measurement Method for Noise Sound Power Level of Forging Machinery) is used To characterize the degree to which the test environment deviates from the ideal, free field condition, the environmental correction value K2A should not exceed 7dB. 5.3 Background noise correction criteria At the microphone position, the background noise measured as the weighted sound pressure level (including wind noise at the microphone) should be at least lower than the measured mechanical sound level 3dB (preferably lower than 10dB), the background noise correction value is calculated according to formula (1). K1 = -10lg1-10-0.1Δ() L (1) where. ΔL---The difference in sound pressure level measured at the specified position when the forging machine under test is opened and closed, the unit is decibel (dB). Note. If ΔL>10dB, K1A=0 is specified; if ΔL< 3dB (ie K1A>3dB), the measurement is invalid; K1A for each microphone position should be determined. 5.4 Environmental conditions during measurement 5.4.1 Indoor test environment 5.4.1.1 The ratio of the equivalent sound absorption area A of the test house to the measurement surface area S should be greater than or equal to 1, that is, A/S≥1 (when A/S=1 Environmental correction value K2A=7dB). 5.4.1.2 Objects that interfere with the sound field should be as far away as possible from the forging machine to be measured, at least outside the measurement surface. 5.4.1.3 The reflecting surface (ground) should be larger than the projection of the measuring surface on the reflecting surface (ground). 5.4.1.4 The ground on which the machine is installed is preferably concrete or asphalt poured. 5.4.2 Outdoor test environment 5.4.2.1 Outdoor measurement should be carried out on open, flat and hard ground, but not on sand, snow or grass. 5.4.2.2 The wind speed should be less than 6m/s during measurement. When the wind speed is greater than 1m/s, a windshield should be added to the microphone. 5.4.2.3 The measurement shall not be carried out under severe weather conditions such as rain and snow. 5.5 Local environment correction value Appendix A gives the determination of the local environment correction value K3, K3 considers the impact of reflected sound on the emission sound pressure level at the designated location. A-weighted When the local environment correction value K3A should not exceed 2.5dB. Note. If the limit of 2.5dB is exceeded, the accuracy of the results will be reduced. GB/T 23281-20096 Test volumeDuring the specified operation period or cycle of the forging machine under test, the basic test quantity at each specified position is the A-weighted sound pressure level L'pA.7 To be quantifiedTo be quantified as the emission sound pressure level LpA at the designated position and the operating position. In order to obtain LpA, the background noise of the basic measurement quantity L'pA needs to be calculated. Fixes and local environment fixes.8 Installation and operation of the forging machinery to be tested8.1 Overview This chapter specifies the relevant installation and operating conditions. For the forging machinery to be tested, if there is a noise test procedure, the relevant Regulation. Noise test procedures for forging machinery should detail their installation, placement, and operating conditions. For large equipment, the installation and operation of the parts, components, auxiliary equipment, power source, etc. of the machine should be determined. 8.2 The position of the forging machine to be tested The forging machine under test should be installed on a reflective surface according to normal use conditions, and should be kept away from any walls, ceilings or other reflections. shot surface. 8.3 Installation of forging machinery during measurement In many cases, the noise emission at the specified location of the forging machine under test is related to the installation conditions. When the forging machinery meets the specified installation conditions , this condition should be used whenever possible. If the specified installation conditions are not available or these conditions cannot be used for the test, the machine radiation caused by the installation used for the test should be avoided Changes in noise, and take measures to reduce the radiated noise generated by equipment installation. 8.3.1 During the measurement, the installation and fixing state of the forging machine to be tested should generally be consistent with the stipulations in the product manual, and the distance from the wall should be shall not be less than 2m. 8.3.2 During the measurement, all the safety devices, noise reduction and sound insulation devices, etc. supplied randomly shall be installed on the forging machinery. 8.3.3 All auxiliary equipment required for the work of the forging machine under test but not part of the sound source shall be located outside the test environment. Otherwise, auxiliary Auxiliary equipment shall be included in the reference body and its working conditions shall be expressed in the test report. 8.4 Operation of the forging machinery during the test 8.4.1 During the measurement, the auxiliary device of the forging machine under test shall act together with the main engine. 8.4.2 During the measurement, the forging machine shall be in no-load continuous operation (driving the working mechanism to operate) or in a single stroke. 8.4.3 Forging machines with adjustable stroke and speed shall be measured at the maximum stroke and maximum speed. 8.4.4 The noise of the tested forging machinery shall be measured according to the test procedure.9 Measurement9.1 Steady-state noise When the tested forging machine is in the specified action specification, it is the radiated "steady-state noise" [that is, the frequency weighting of the sound level meter is used at the observation time "A", when the time-weighted characteristic is "slow", the fluctuation of the indication value is less than ±3dB (A) noise], the observation time shall not be less than 15s, and the reading is Take the average value of the maximum and minimum indications of the sound level meter during the observation time. 9.2 Unsteady Noise When the tested forging machine is in the specified action specification, it is the radiated "unsteady noise" (that is, the sound pressure level changes significantly during the observation time) noise, that is, when the frequency-weighted "A" and "slow" time-weighted characteristics of the sound level meter are used, the fluctuation of the indication value is greater than ±3dB) , measure with an integrating sound level meter. Periodically changing non-stationary noise can also be measured by the "slow" time-weighted characteristic of the sound level meter. The sound pressure level and duration of each cycle were recorded to calculate the average value of one cycle. GB/T 23281-2009 ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 23281-2009_English be delivered?Answer: Upon your order, we will start to translate GB/T 23281-2009_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 23281-2009_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 23281-2009_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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