Sampling techniques for securing representative long-term equivalent noise level using environmental noise automatic measurement system data

This study was undertaken to present a useful manual measurement method guideline in order to overcome the limitations of short-term measurement, increase the accuracy and secure the representative long-term equivalent noise level. The data was obtained from 4 selected sites in Seoul and 4 sites outside of Seoul out of the noise automatic measurement system installed in 62 sites. The probabilities of data being included in error range for quarterly equivalent noise level using each quarterly L_eq,5min data throughout the year 2010 were used for error evaluation in each of the sampling techniques. The results of probability analysis for the daytime period showed more than 60% probability from 10 am to 2 pm and from 9 pm to 10 pm. On the other hand, increasing the number of random sampling was the higher increasing rate of probability than lengthening time length. That means the results for random sampling technique are more accurate than results obtained by the consecutive sampling technique. Therefore, in consideration of the main objective and efficiency, the application of the results of probabilities for daytime period and probabilities for sampling techniques analyzed in this paper is expected to measure the more representative and accurate noise level.