Operating instructions

LOCAL OPERATION
3-66
SINAD
Selects SINAD as the measurement method. The AF generator is set to 1 kHz and the 1 kHz
distortion notch filter is switched alternatively in and out of circuit, with the signal level being
measured by the AF voltmeter in each state. See Fig. 3-10 a, b, & c, Distortion level and signal to
noise level measurements, on page 3-36.
The monitor software calculates the SINAD level according to the formula:-
SINAD
= 20
1
2
log
V
V
dB
=
++
+
20 log
()
()
S
N
D
ND
dB
The distortion bar chart ranges available are 0 to 18 dB and 0 to 50 dB. The SINAD level is
displayed as a digital readout above the bar chart. The AF test menu is recalled automatically after
pressing this key.