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Frequently Asked Questions

Noise Nuisance Assessment with Input Keypad

Noise Nuisance Assessment with Input Keypad
The XL2-TA Sound Level Meter is the first type approved sound level meter with a certified input keypad for legal noise nuisance assessment. The Physikalisch-Technische Bundesanstalt (PTB) in Germany confirmed, that the XL2-TA in combination with the external Input Keypad meets the requirements of the standard IEC 61672.

The Input Keypad forms an ideal extension for the XL2-TA Sound Level Meter to monitor environmental noise. Any noise event can be marked during the ongoing measurement and audio files recorded simultaneously. The Keypad offers four marker keys for triggering an event recording or categorizing the type of noise during the measurements.

Immediate marking of Noise Events during Measurement
Noise measurement specialists may distinguish between four individual noise types by using the input keypad. Pressing any of the four keypad buttons will be recorded in the log data. These markers can be utilized e.g. for monitoring of an industrial site with different noise sources: Button 1 for in- and outgoing traffic, button 2 for a noise machine in the yard, button 3 for the fork lifts. Button 4 can be reserved for other noise sources outside the factory, such as a passing ambulance or a mower in one of the neighbors gardens. This approach simplifies the data analysis later with the XL2 Data Explorer Software where the level-time graph is displayed clearly showing the time and duration of the various markers. The broadband levels and the spectral noise data for the marker are available on-the-fly. The respective marker categories can be renamed according to the sound sources they are related for identification in the resultant report. The ambient noise marker is defined as an exclusion marker, thus these time periods are automatically excluded from the data set and the subsequent calculations (e.g. LAeq level or percentile statistics).

Annoyance Markers activated by a Complainant
Unattended noise monitoring often bears the challenge of finding the noise events of interest within a large amount of measurement data. This is very much simplified if the complainant presses a keypad button when disturbed by a noise event. The Input Keypad is connected directly to the XL2-TA Sound Level Meter by an extension cable. The measured noise emissions of an industrial plant or noisy neighbor can now be easily complemented by a subjective impression, identified by the four key marker categories. The Input Keypad allows the instrument to be locked away, e.g. in a protective case, and the complainant only has access to the Keypad which is used to mark any disturbing noise. A green LED on the Input Keypad confirms a successfully registered key press. The XL2-TA may be configured to record the audio data as a wav-file during the event for identifying the annoying noise sources. The sound level meter and its accessories are locked in a protective case forming an ideal and simple system for reliable and legally compliant assessment of noise nuisance complaints.

Faster Analysis with XL2 Data Explorer Software
Each recorded marker is logged in the log file. When importing the measurements into XL2 Data Explorer, the markers are displayed with their respective marker type and may be analyzed individually or as groups for their levels, time of day, spectral content or alternatively to exclude non-nuisance events from nuisance calculations.

XL2-TA Sound Level Meter for Noise Monitoring
PTB Germany have now type approved the configuration of the XL2-TA Sound Level Meter with the Input Keypad. This offers a dedicated solution for legal noise annoyance monitoring, e.g. for community noise or neighbor noise nuisance investigation. The Input Keypad functionality requires the optional Extended Acoustic Pack installed on the XL2-TA Sound Level Meter. All XL2s can be upgraded to the Type approved XL2-TA.


Read more about noise level monitoring here.
Download the full PTB type approval certificate here.

Contact NTi Audio for more details here.

Press Picture(s) for download here.