Class 1 Portable Noise Monitoring System

As unattended short - to medium - term noise monitoring is a common requirement for consultants and local authorities, Brüel & Kjær (UK) has launched an ‘Allweather Case’ to protect un-manned equipment.

The new 3535 ‘All-weather Case’ is a compact and light-weight enclosure for the noise monitoring system, which includes a sound level meter and outdoor microphone. As measurement integrity is crucial for noise

measurement, uniquely the combination of the 2250 Noise analyser and 4952 Outdoor microphone are Typeapproved to provide Class 1 measurements to IEC 61672-1:2002. This ensures that the measurement system

complies with the minimum requirements of accuracy for unattended noise measurement, a consideration often overlooked in portable noise monitoring systems.

Two small slim-line Lithium Ion battery packs provide the power to operate all equipment inside the case. The Lithium Ion battery has five times more power-toweight ratio than equivalent lead-acid batteries traditionally used in similar systems. This provides 12 days of day-time monitoring with a case weighing less than 7 kilograms and can be re-charged in the case, ‘hotswapped’ in-situ allowing un-interrupted measurement or

run off mains electricity supply.

High speed, internet based communication is provided by one of the 3G or GPRS modems supported in the case design, allowing remote data retrieval and monitoring of the real-time noise levels. Events, such as

noise conditions, low-battery power levels, memory storage status, calibration status and many other userprogrammed trigger conditions are instantly e-mailed or sent by SMS text message to the user’s PC or mobile phone.

The 3535 supports the new SDHC high capacity standard for SD memory cards, which allow up to 32GB of data storage on one SD card offering the convenience of long periods between data retrieval tasks, with the

flexibility to store long duration, high quality sound recordings to enhance assessment.

As measurement integrity is very important in any noise monitoring exercise - particularly when the system will be left unattended for many days or even weeks – the patented Charge Injection Calibration allows regular

auto-checking of the measurement system to ensure the continued and accurate operation of the unsupervised monitoring system.

Brüel & Kjær’s 3535 case is suitable for many different environmental applications including environmental impact assessment & planning, building construction noise assessment, concert/sports venue licensing, assessment of road, railway and aircraft noise, industrial process licensing and noise map validation.