Audio Analyzer Measurement Functions 5
U8903A User’s Guide 99
The following figure shows the noise level measurement.
Figure 5-11 Noise level measurement
SMPTE intermodulation distortion (SMPTE IMD)
The SMPTE IMD function provides a measure of the second
and third order intermodulation distortion introduced by the
UUT by injecting two pure tones (tone 1 and tone 2, where
tone 1 is at a much lower frequency than tone 2, for
example, 60 Hz and 7 kHz respectively) into the UUT.
SMPTE IMD is expressed in dB (default) or as a percentage.
If tone 1 = f1 and tone 2 = f2, the following harmonics are
considered.
• f2 – f1
• f2 + f1
• f2 – 2f1
• f2 + 2f1