GB 14892-2006Noise limits and measurement methods for urban rail transit trains (English PDF)

1 Scope

GB 14892 sets the noise limits for metro and light rail trains and the methods for measuring them, inside the driver's cab and inside the passenger saloon, together with the requirements for the test report. It fixes the running conditions under which the measurement is made and the instrumentation, so that figures from different lines and different builders are comparable - which matters because interior noise is one of the acceptance criteria when a city takes delivery of a fleet. It replaces GB 14892-1994 and GB/T 14893-1994. Issued on 7 February 2006, in force since 1 August 2006. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the edition it replaces are taken from there. The clause text, the tables and the numeric limits are not reproduced on this page - they are in the document itself, which is delivered in full in English translation.

This standard specifies the main contents of noise limits, measurement methods, test reports for urban rail transit. This standard applies to the design, manufacture, inspection of subway and light rail trains in urban rail transit systems.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties agreeing to this standard are encouraged to investigate the possibility of using the latest versions of these documents. For undated references, the latest version applies.

GB/T 3785 Electric, sonic properties and measuring methods for sound level meters

GB/T 8170 Rules for rounding off of numerical values

GB/T 15173 Sound calibrators

GB/T 17181 Integrating-averaging sound level meters

3 Terms and definitions

The following terms and definitions apply to this standard.

3.1 Equivalent sound pressure level Leq, LAeq, T If, within a specified time, the A-weighted sound pressure of a continuous steady- state sound has the same mean-square A-weighted sound pressure as time-varying noise, then the sound level of this continuous steady-state sound is the equivalent sound level of this time-varying noise. Note

1.The unit of equivalent sound level is decibel (dB). Note

2.The calculation of equivalent sound level is shown in formula (1). Where. LAeq, T - Equivalent sound level, in decibel (dB); t2 - t1 - Specified time interval, in second (5); PA (t) - Instantaneous A-weighted sound pressure, in Pascal (pa); P0 - Reference sound pressure (20 µpa). Note

3.When A-weighted sound pressure is expressed as A-weighted sound level LPA (dB), the calculation formula is shown in formula (2). [GB/T 3947-1996, Definition 13.7]

3.2 Background noise When the train's operating position is far from the measuring point, meanwhile the effect of train operating noise can be ignored, environmental noise is not considered.

3.3 Vehicle A single-unit passenger train that uses wheel-rail load support, has traction power or no traction power, can be assembled into a train.

3.4 Set of cars A combination of vehicles arranged into fixed basic operating units, capable of operating independently on tracks.

3.5 Train An assembly of one or more sets of cars assembled for the purpose of operating on an operational line.

3.6 Maximum running speed The highest speed permitted for train operation.

3.7 Monitoring test A test conducted for product quality supervision, acceptance, manufacturer self- inspection.

4 Noise limit requirements

The maximum permissible limit for the equivalent sound level (Leq) of subway and light rail trains in urban rail transit systems shall comply with the requirements of Table 1.

5 Measurement method

5.1 Measured quantity The measured quantity is the equivalent sound level Leq in the fast (Fast) range under specified measurement conditions inside the vehicle and outside the train.