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The sound environment surrounding scrap metal recycling company Ragn-Sell’s facility in the city of Västerås is a complicated one. The municipality requires regular noise control, but between the facility and the nearest residential area there is both a rail line and an automobile road. There are other sources of noise in the area as well.

“We began with near field measurements of noise sources within Ragn-Sell’s facility,” says Paul Appelqvist of ÅF-Ingemansson, the company in charge of the assignment. “From this measurement data we put together a noise map, which allowed us to make changes in the operation, and thus approved noise levels in the residential area were reached.”

A control plan with measurements conducted for one week every 6 months has now been in place for 5-6 years. With the help of the INFRA equipment, S50, the company has been able to separate the various sources of noise and report them in the measurement data so that guidelines set forth by the municipality are not exceeded.

“At first we had another contractor supplying measurement equipment, but there were breakdowns and malfunctions, and the equipment had no means of remote control. The INFRA equipment is reliable and weather proof, even the master unit is impervious to bad weather. And in addition, there is no power source required. Battery life is fine for our measurement periods, and the equipment is easy to operate remotely,” says Paul.

Remote controlled trigger levels
In addition to isolating noise sources outside Ragn-Sells, it is important to set the correct trigger levels and adjust them further when changes occur in the sound environment.
“At the chosen trigger level we also record a sound sequence so that we can later clarify the sound source. We have learned from the complaints of the local residents that the disturbing noise comes from other sources, and not Ragn-Sells”, says Paul.

It is a big advantage that parameters can be remotely configured. For example, trigger levels can be adjusted from ÅF Ingemansson’s office in Solna, even during an ongoing measurement period.
“We are now looking forward to INFRA Net, which will simplify things even more. The client will be able to follow the measurement process live on the Internet as it occurs,” says a happy Paul Appelqvist.