Larson Davis SoundAdvisor 831C Reference Manual page 24

Under Range Icon
FIGURE 2-13 Under Range vs. Normal Range Data Display
OBA Overload Icon
SoundAdvisor Model 831C
When using a microphone having a sensitivity of 50 mV/Pa, the input
overload will occur approximately as shown in Table 2.3.
Table 2.3 Input Overload Levels
Input Gain, dB
When the signal from the preamplifier drops to the point where the
noise level of the instrument and the preamplifier influence the
measurement, an under range condition exists. When this happens the
Under Range Icon will appear.
FIGURE 2-12
As long as the under range condition exists, the icon will flash. When
the measured level no longer produces an under range condition, the
icon will be removed from the display.
At any time when a measured parameter is in an under range condition,
its numeric display will alter in color, as shown in Figure 2-13.
Under Range Display
If the input to the Octave Band Analyzer becomes overloaded, the OBA
Overload icon will appear to indicate the overload.
FIGURE 2-14
This icon operates similar to the Input Overload Icon shown in the
above section "Input Overload Icon".
Displays and Icons
0
20
Under Range Icon
Normal Range Display
OBA Overload Icon
Overload Level, dB Peak
143
123
2-10