21
frequency weighting A/C line
The frequency of the measuring signal is weighted with the help of two benchmark
•
curves.
Line A represents the characteristic hearing line of the human ear. Humans perceive
•
deep sounds as quieter than mid or treble sounds.
Line C weighs the frequency spectrum linear and without filter (actual sound level).
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Time rating fAST/SLOW
The signal can be measured with two different measuring intervals.
•
For rapidly changing sound levels (horn, shot, etc.), you have to set the time rating to
•
„FAST“. The measuring duration is 125 ms/measuring operation.
For slow and persistent sound levels (noise, humming, etc.), the time rating must be
•
set to „SLOW“. The measuring duration is 1 ms/measuring operation.
STARTING THE mEASUREmENT
9.
You should always measure a sound source directly and at a distance of 1 m. Make
•
sure that there are no objects or persons between the microphone and the sound
source.
Point the sound level meter with the microphone directly on the sound source.
•
In order to not influence the soundwaves, keep the measuring as far away from
•
your body as possible at your outstretched arm or attach it to the enclosed stand.
If possible, move approx. 2 m away from the measuring spot. Avoid vibrations or
movements.
In case of wind (>10 m/s), use the enclosed wind protector to not falsify the measuring
•
value with the wind noise. The wind protector does not falsify the measuring value.
First you must program the data logger (see chapter “Programming the data logger”).
1.
If you have selected the “Manual” function, hold down the Data Logger button for two seconds to
2.
start the measurement.
If you have selected the “Automatic” function, the data logger starts the measurement automatically
3.
after you have completed programming the data logger.
During the measurement, the green LED flashes at the frequency set in the “LED Flash Cycle
4.
Setup”.
After the preset recording rate has been reached, the recording is stopped automatically.
5.
To stop the measurement manually, hold down the Data Logger button for two seconds.
6.
Once the memory of the data logger is full, the measurement is terminated automatically.
7.
The recording can also be terminated at any time by displaying the readout on the computer before
8.
the recording is complete (see chapter “Displaying data logger readout”).
