A-4
Reference Level
Model 820 Technical Reference Manual
The data in the above table was obtained by electrically testing
a number of instruments. For all electrical tests, the micro-
phone was replaced with an equivalent electrical impedance
(Larson Davis ADP005 microphone adapter).
Other Detectors
• Weighted Peak Detector = 85.0 dB
• Unweighted Peak Detector = 38.0 dB
• AC Output = 88.0 dB
• DC Output = 105.0 dB
Reference Level
The reference level is 114.0 dB SPL.
Frequency Weightings
The available frequency weightings for the Models 820 are
described in the table below.
NOTES:
1. The RMS frequency weighting is selected via parameter
#40, “Frequency Weighting”. The Weighted Peak Detector,
and DC Output frequency weighting always matches the RMS
Detector frequency weighting.
Detector
A Weight
C Weight
Flat Weight-
ing
RMS
√
√
Weighted Peak
√
√
Unweighted Peak
√
√
AC Output
√
√
√
DC Output
√
√
