Microphone Calibration - Phonic PAA3X Manual Del Usuario

Octave – The octave option allows users to
select the resolution of their RTA. There are two
options available: 1/3rd and 1/6th octave. In es-
sence, the 1/3rd option is a 31-band RTA while a
1/6th octave has much finer resolution – almost
twice the detail – at 61-bands.
Weighting – Any audio analyzer needs to be
designed so that it hears sound properties in
a manner that would be appropriate for the
measurements it is taking. For example, the
sensitivity of human hearing is restricted to the
frequency range of 20 Hz to 20 kHz. The human
ear, however, is most sensitive to sounds in the
range of 500 Hz to 8 kHz. The ear becomes
progressively less sensitive to sound out of this
range. Microphones, however, are not restricted
by this limitation and therefore do not respond in
the same manner that our ear would.
Audio analysis devices such as the PAA3X pro-
vide various weightings for the measurements
taken to compensate for the increased and
decreased sensitivity. The weighting determines
the curve that the PAA3X will use to interpret the
input signals from the chosen input source. Flat,
A-, B- and C-weightings are available. Each of
these weightings is ideal for different applica-
tions, with A-weighting perhaps being the most
commonly used (and that which most closely
matches the human ear) and internationally
recognized standard for measurement.
Unit – This allows users to adjust between vari-
ous measurement units. This may include dB
SPL (when the microphone is selected as the
input source), dBu, dBV and Volt (when line is
selected as the input source).
Peak Hold – The peak hold function will cause
the highest signal peaks on the RTA to be held
for a short period of time, giving a better visual
representation of these high peaks. This is
represented by a small red line/dot at the top of
the frequency bar. This red mark will remain for
as long as the peak hold time is set, or until the
signal rises above the previous peak.
PAA3X
EQ Setting – Selecting this option will allow you
monitor the suggested equalizer band settings
– updated in real time. Please consult the EQ
Setting section on page 8 for more info.
Calibration – Entering this menu will allow users
to calibrate the precision microphone. See the
calibration section below for more information.

MICROPHONE CALIBRATION

As the PAA3X comes factory calibrated, you
should never actually need to calibrate your unit.
If measurement data or the operation of the unit
begins to seem abnormal, however, it may be
necessary to perform a calibration. Anyone can
calibrate the PAA3X and regain accurate sound
pressure level measurement. This is provided
they have a quality sound level calibrator with
1/2" diameter adapter that sends out a 1 kHz
tone. A B&K TYPE 4231 sound level calibrator
is suggested.
Procedure:
1. Enter the Main Menu > Setup menu.
2. Place the PAA3X's microphone within a
sound level calibrator with a microphone
connector of 1/2" diameter.
3. Select the RUN/STOP icon on screen to start
the calibration process.
4. Scroll to the 'dB' level in the middle of the
screen and press enter to edit.
5. Adjust the level measured from the SPL cali-
brator by pressing the ↑/← and ↓/→ buttons
until the level is equal to that of the sound
level calibrator (typically 94 dB). Pressing the
↑/← button once will increase the value by
0.1dB; pressing the ↓/→ button each time
will decrease the value by 0.1 dB. This can
also be accomplished using the jog wheel
control.
6. Press enter and select the SAVE icon to
complete the calibration (the PAA3X will
restart in this case) or select the "CAL MIC"
icon to exit without saving.
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