HWM DXmic User Manual page 18

Adjustable Filters – Bandpass Centre
Frequency.
The position of the centre frequency can be
adjusted up or down the spectrum using the
left and right arrows
MLP (Minimum Level Profiling) is performed by stepping along the line of the suspect pipe and
recording the sound levels. The ground microphone is placed on the ground and the sample
button pressed momentarily. The DXmic then records the minimum noise over three seconds.
As each measurement is taken the histogram graph is built up showing the difference between
each reading visually and numerically, making noise level comparison a simple task.
For each measurement taken a number appears to the right of the histogram. This noise level
value is a relative indicator for each measurement. Once several readings have been taken the
operator can select a sample by pressing the < or > buttons either side of the graph. The
numerical noise level value is then shown for each measurement.
DXmic can store up to 100 measurements.
MLP Mode Screens
Once filters have been selected go to the MLP (Minimum Level Profiling) screen by pressing the
'MLP Mode' button in the bottom right hand corner, to carry out a leak noise comparison. The
following screen will appear:
MLP Mode
Adjust position
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