XL2 Data Explorer Software now calculates Rating Level Lr

XL2 Data Explorer Software now calculates Rating Level Lr

The Data Explorer Software offers wide ranging analysis and reporting on measurement data from the XL2 Sound Level Meter. The very latest Data Explorer release, version 1.50, further extends the data post-processing capabilities. Tonal and impulsive sounds can now be marked automatically and penalties applied in accordance with the ISO 1996 standard. Data Explorer also calculates the Rating Level Lr for the assessment of compliance with noise limits.

The XL2 Sound Level Meter provides all the necessary broadband levels, third-octave spectra and uninterrupted audio recording for the complete measurement period. The measurement location is normally chosen as the position where the limits prescribed by the standards are most likely to be exceeded. The data is then imported into the Data Explorer Software for calculation of the average noise levels over reference time intervals.

Automatic Identification of Tonal and Impulsive Sounds

Prominent tones or impulses cause increased annoyance. In a noise assessment, it is therefore necessary that these specific characteristics be rated accordingly. In this regard a penalty is added to the measured average sound pressure level LAeq. Data Explorer automatically identifies and marks the time periods containing the tonal and impulsive sounds. Markers label the relevant events and these may then be verified with subjective assessment by playing the recorded audio file through the PC speakers or headphones. For example, penalties applied to sounds that are actually not that annoying can be reduced or removed, while additional penalties can be added to sounds that are highly impulsive or tonal allowing the operator to assess the all-important context.

Further Tools Complete the Analysis

Additionally, level markers can be set for penalties to be applied to short duration high level noise events. At the same time, the contribution of extraneous noise that is not caused by the sound source under investigation can be eliminated from the calculations. To determine periods with low-frequency noise, the software automatically applies markers, for example, on the level difference between LCeq and LAeq.

Comprehensive Determination of Rating Level Lr

After completing the noise exposure analysis, Data Explorer determines the Rating Level Lr. This corresponds to the sum of the average noise level, including penalties for tonal, impulse and special sounds. The rating level calculation is performed for all specified time intervals in accordance with ISO 1996 or using custom intervals; e.g. with 1 hour periods during the day from 07:00 h to 23:00 h and a shorter period of 15 min at night from 23:00 h to 07:00 h. Separate Lr criteria for the weekend period completes the comprehensive analysis of the measured data.

Comply with Maximum Emission Standards

The rating level Lr is the specific sound level plus any adjustment for the characteristic features of the sound within the assessment period. It is compared against the maximum permitted noise level, such as 70 dBA in industrial areas or 50 dBA in residential areas.

In summary, the XL2 Sound Level Meter in combination with the XL2 Data Explorer software are the ideal tool set for professional noise recording, data analysis and reporting.

The Data Explorer software V1.50 is free to download for all XL2 users and can be installed on as many PCs as required. The process of importing data from an XL2 Sound Level Meter into the software requires that a Data Explorer option be installed on the XL2.