GB/T 41971-2022 in English

Analysis of the core content of the standard

This standard specifies the measurement method of the A-weighted sound pressure level of agricultural and forestry tractors in motion, focusing on solving the noise assessment problem of elastic tires and rubber crawler agricultural machinery. Compared with ISO7216:2015, the main technical differences are:

Key technical requirements

1. Measuring instrument specifications

A Class 1 accuracy sound level meter (in accordance with GB/T3785.1) must be used, and a Class 1 sound calibrator must be used for verification before and after measurement. If the deviation exceeds 0.5dB(A), the data will be invalid. The calibrator must be traceable to the national benchmark every year.

2. Test environment control

• Site requirements: open area with a radius of 50m, concrete/asphalt ground within 20m
• Weather conditions: temperature -10℃~35℃, wind speed ≤5m/s (1.2m height)
• Background noise: must be 10dB(A) lower than the measured value

Implementation points and cases

Analysis of Standard Evolution

Based on ISO7216, this standard strengthens the operability: adding engine power verification (≥95% of the calibration value), clarifying the highest gear test, standardizing speed records and other requirements. These improvements are based on the actual measured data statistics of 12 mainstream agricultural machinery companies from 2018 to 2020.

Implementation Suggestions

1. Give priority to the windless early morning period for testing to avoid environmental interference
2. Establish a two-person review system for acoustic calibration to ensure the status of the instrument
3. Pay special attention to the impact of ground reflected noise on crawler models