Noise logger for
Acoustic zone monitoring (AZ)

With our noise loggers a continuous monitoring of the pipeline regarding leakage noises is possible.
They are an alternative to a regular check by 'tapping' with correlator or stick-microphone.
Different to the manual tapping, other noises like noise caused by traffic or consumation of water (f.e. by washing machines) do not disturb the leak detection. The noise loggers are therefor particularily suitable for the pre-detection of leakages in the city area or at busy main streets.

The devices are installed - depending on the structure of the line network - in a distance from 100 to 500 m. They can be put, by means of their compact form, in UF fire-hydrant claws or on valve-nuts. The caps can still be closed. There they register possible leakage noises in the line over a sensitive special microphone and register the noise intensities.
The noise data are picked out after the measurement (duration at least 1 night) by a Notebook or one of our correlators (except PAL 300).
Afterwards the loggers can also be used in another place. Fast and flexibly.

Approximately in summer 2001 we will offer a further version of the noise loggers.
These loggers will be conceived regarding power supply and data transmisson for continuous use at a place. A constant network monitoring without transferring the logger will be ensured that way. They will be read out just by driving down the roads directly from the vehicle (radio transmission by close range senders).

On the basis the noise curves you can determine quickly and surely weather there is a leakage (noise) near the measuring point or not:


Directly inserted into the fire-hydrant clamp the highly sensitive noise loggers listen on leakage noises and register them.


Upper curve:
The minima do not decrease/go back on zero.

In the proximity of the loggers is a leakage.


Upper curve:
The minima decrease/go back on zero. The ' peaks ' between them result from brief extraneous noises, e.g. vehicles driving by.

No leakage

A that way found leakage can now be fine-located with correlator and ground microphone.

In a mains monitored with the noise loggers, newly occurring leakages can be found fast and thus losses of water can be permanently held down and many water damages like floated cellars and road-breaks can often be avoided.


 URL:  http://www.lindenberg-ortungstechnik.com/eng/seite240.html PAGE updated:  12.02.02
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