Pulsar Instruments Plc

Pulsar noise testing equipment for environmental noise monitoring - Environmental - Environmental Monitoring

Environmental noise is a major issue in most countries, especially in areas of high population, and the sources of noise and their adverse effects on our well-being are varied. In terms of assessing the impact of these issues, we need to be able to make suitable noise measurements, or in some cases monitor the noise levels for longer periods.

Environmental noise is very different to workplace or industrial noise because the level of annoyance or nuisance can be very subjective and will elicit diverse reactions from different people.

Examples of typical noise sources:

  • Industrial Sites
  • Construction Work
  • Road Traffic
  • Animals (Dogs barking)
  • Aircraft noise
  • Entertainment venues

Environmental noise can also have different characteristics:

  • Continuous
    • Extraction Fans, compressors etc
    • Road traffic
    • Industrial Processes
  • Intermittent
    • Transport
    • Construction
    • Animals
    • Industrial Processes
  • Broadband (Noise that has a fairly even tone content and less annoying)
  • Tonal Noise (Noise that has dominant tone(s) that can be very annoying)  
    • ‘Whining’ machinery
    • Low frequency noise that causes vibration within surrounding buildings etc.
    • Wind turbines

Sound level meters for environmental noise

1. Basic noise level checks or ‘spot checks’

Often you need to take quick decisions and understand if there are likely to be any noise issues. By using a simple sound level meter such as the Model 14 Digital Sound Level Meter you have a cost-effective, compact and ‘easy to use’ instrument that can be easily transported, allowing you to make a quick judgement regarding noise levels. This is particularly useful where a more expensive instrument would be cumbersome and more prone to the risk of damage or misuse.

The Model 14 is supplied with a windshield as standard to protect the microphone capsule and has two selectable ranges to allow you to quickly gauge both environmental and industrial level noises. The instrument is compliant with IEC 61672 and can be supplied with an acoustic calibrator if you wish to verify your measurements – as really should be done.

2. Single but more detailed measurements

Environmental requirements and legislation vary based on your country, locality and specific circumstances.
Often a handheld integrating sound level meter such as the Pulsar Nova Model 45 (Class 1) would be mounted on a tripod at a boundary position and, for example, a 15-minute measurement made. Often it is necessary to make a series of similar ‘fixed duration’ measurements and store these into the instrument's memory (for subsequent analysis) for which the Nova is ideal.

The usual stored information may consist of the ‘A’ Weighted Leq, LN values, SPL values and perhaps 1:1 Octave Band information for tonal analysis.

Sometimes we need to monitor noise levels on an ongoing level and make longer measurements sub-divided by shorter measurement durations such as 5 minutes, 15 minutes or 1 hour. This allows us to look at, for example, a 24 hour period and find the average, background or maximum noise levels for every 15 minute period throughout the day. This gives us a much clearer picture of noise patterns and how they can be controlled to minimise their impact on the wider community. Often, lower noise limits will be set during the late evening and night due to the extra impact of any noise.

We have a number of outdoor noise measurement kits that can transform a handheld sound level such as the Pulsar Nova Model 45 (Class 1 meter) into an environmental noise monitor for mid to long term noise monitoring.

Typical view of a 1:3 Octave Band Analysis using Acoustic Toolbox software.

Sometimes 1:3 octave measurements are required for tonal noise, or for more detailed analysis of the frequencies of the noise. In this case, we recommend the Model 33 Real-Time Analyser - for real-time sound measurement across all the frequencies at the same time. 

There are many engineering solutions available to reduce noise levels and by performing a 1:3 Octave Band Analysis before and after this work you can determine and report the effectiveness of such improvements.