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SAM: the Spectro-Acoustic-Meter.

SAM is the latest technology development from Atkinson & Rapley Consulting Ltd in association with Astute Engineering. It is a pc-based system for measuring and analysing environmental noise.

SAM utilises the latest virtual instrumentation approach to programming, creating a very user-friendly interface built on a modular foundation.

SAM is a PC-based solution to the complex problem of how to measure and analyse environmental noise. Current technological solutions are usually based around dedicated instruments. They have a singular purpose and function. SAM is a computer which has extended functionality specific to the requirements of environmental noise officers.

SAM is unique in that it utilises two input signal sources (microphones) which allow a single instrument to make two sets of measurements simultaneously in real time. This allows for the measurement of sound inside and outside a dwelling, for example, with one instrument.

The audio spectrum SAM uses is 20 HZ to 20 kHZ at sound levels nominally in the range of 30 to 120 dB. Sound is sampled from the environment in linear mode, however the results can be displayed in: A-weighted; C-weighed or Linear (Z-weighted). Spectral analysis is available in: 1 octave; 1/3 octave; 1/6 octave; 1/12 octave and 1/24 octave, making it unique among sound analysis systems. In addition, the common acoustic statistics of L10, L50, L90, L95,Leq and Max are always available in a table.

Sound levels can be displayed in real time on interactive graphs.The sound spectra are similarly available. A separate dual-bar graph displays the instantaneous combined sound power for each channel.

Another unique feature of SAM is the ability to record actual sound bites when a pre-set dB threshold is exceeded. In this way, SAM acts like a digital ‘tape-recorder’ - the recorded sound files can be used as evidence at a later time. After a sound bite has been recorded, the user can set a holdoff period such that even if the sound exceeds the threshold again, no recording will be made until the holdoff period has elapsed. Recorded sound bites are displayed on the dB/time graph as yellow dots, that are in fact buttons - clicking on them plays the sound file.

SAM has the added advantage that it can be operated in two distinct modes: real-time or batch mode. In real-time, SAM can be used as a roving sound inspector, determining the origin of a particular sound. Alternatively, SAM can be set up in batch mode where a time and date calendar can be set up in advance, off site. When SAM is placed on site, the batch job(s) can be activated and will automatically start recording data at the appointed date/time. On completion SAM simply goes into sleep mode. Data can be downloaded automatically over the internet to your office if required, at a specific time set by the user. This allows environmental officers to interrogate a SAM field station on an ongoing basis without ever leaving the office.

SAM has been designed with council environmental inspectors in mind. The system can print out a cessation order on the spot with the use of a portable printer. Word templates can be simply filled out with the offender’s details and printed on the spot. The system automatically includes graphs of the alleged noise infringement including spectral analysis and acoustic statistics as proof. This really is the equivalent of a ‘speeding ticket’ for noise infringement.

SAM V.2.0 has a new feature to assist noise abatement officers in the field: the One Touch Button. Turn on the laptop with the interface unit plugged in and simply push the single button to make a 5, 10 or 15 minute spot recording and then print the infringement notice.