Maxpip - Elcometer Protovale 331 Operating Instructions Manual

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OUND MODE ETECTION MODE
However, if the sensitivity has been adjusted to an arbitrary level, the necessary
degree of consistency may not be achieved.
To improve audible resolution when locating closely spaced reinforcement bars
it may be beneficial to reduce the sensitivity below the optimum level described
in the previous paragraphs.
It is also possible to reduce sensitivity deliberately so that bars of adequate
cover are not indicated, but bars of shallower cover are. You may find this
technique to be a simpler and quicker method (albeit somewhat less precise)
than the Under Cover mode described later; but please note that both methods
share the same disadvantage that they only indicate bars with shallow cover,
but do not confirm the presence of bars with adequate or deeper cover.
During a search the sound from the speaker and the brightness of the LED may
reach their maximum level before the signal has reached its maximum. If this
occurs, reduce the sensitivity until the sound and LED are again responding
readily to changes.
Note: Reducing the sensitivity does not reduce the overall sensitivity of the
instrument, but will reduce the sound and LED indications to zero when the
search head is removed from the region of high signal strength. This may cause
deeply covered bars to be missed.
If the sensitivity is reduced to the minimum setting, the locate
sound is muted (indicated by a crossed-out loudspeaker
symbol on the screen).
The sensitivity setting only affects the locate sound and the
brightness of the LED on the search head; it does not affect the cover
measurement or the size measurement.

10.2 Maxpip™

This is an alternative method of locating the centre of each reinforcement bar.
In this mode, an audio 'pip' is given each time the middle of a reinforcement bar
is detected as the surface is scanned.
An icon on the main measurement display indicates that
Maxpip™ mode is active. When Maxpip™ mode is active, the
normal locate sound is suppressed.
In practice, since it is not possible to be sure that you have
reached maximum signal until the signal has started to decrease again, the pip
always occurs just after you have passed the actual position of the bar, and this
inevitable lag varies with scanning speed. Therefore the Locate mode is far
superior for audible location.
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