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D) RESPONSE TO SHORT DURATION SIGNALS
a) Select L
A1”
.
b) Adjust the level of a reference 4 kHz sinusoidal signal to indicate 94,0 dB.
c) Select L
A10”
.
d) Apply a continuous sequence of 4 kHz tonebursts of 1 ms duration, with an amplitude
equal to the reference signal, and a burst ratio of 1/100. Note the value measured.
e) Calculate the difference between the measured value and the level of the reference
signal.
∆L = L
A10”
– 94dB
f) Repeat points d) - e) with a burst ratio of 1/1000.
g) Repeat points d) - f) with tonebursts of 10 ms duration.
h) Repeat points a) - g) with a reference sinusoidal signal of 4 kHz and 140,0 dB.
E) RESPONSE TO UNIPOLAR PULSES
a) Select L
A1”
.
b) Adjust the level of a reference sinusoidal signal of 1 kHz to indicate 135,0 dB.
c) Select L
A10”
.
d) Apply a sequence of positive-going, rectangular, unipolar pulses of 0,5 ms duration,
separated by 10 ms with a peak level equal to the rms level of the reference signal.
Note the value measured.
e) Repeat with negative-going pulses.
f) Calculate the difference between the indication with the positive-going pulses and the
indication with the negative-going pulses.
∆L = L
A10”p
– L
A10”n
where:
L
A10”p
- Level measured with positive-going pulses
L
A10”n
- Level measured with negative-going pulses
F) OVERLOAD INDICATOR
a) Select L
A1”
.
b) Adjust the level of a reference sinusoidal signal of 1 kHz to indicate 140,0 dB.
c) Select L
A10”
.
d) Apply a 4 ms toneburst of 1 kHz with an amplitude equal to the reference signal.
Note the overload indicator.
e) Repeat with a pulse 3 dB greater.
G) SOUND EXPOSURE
a) Select L
A1”
.
b) Adjust the level of a reference sinusoidal signal of 1 kHz to indicate 94,0 dB.
c) Select E.
Note the value of E with measurements of 1”, 10” and 1’.
d) Repeat with a reference sinusoidal signal of 120,0 dB.
e) Repeat with a reference sinusoidal signal of 140,0 dB.
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