Sound level meter - Frequently Asked Questions

Both outputs have an output resistance of 50Ω ±2%, but they are not capable of driving a 50Ω termination resistor. Always use an instrument with an input impedance of 10kΩ or higher.

1. AC output

The AC output contains an error (up to 15%), so be sure to calibration with an electrical calibration signal before use. In normal and wide-range AC output modes, the analog-processed signal is output directly. During dual measurement, the main signal is output.

When the octave filter option is used, the signal that has passed through the digital filter is output from the D/A converter. In this case, the sampling rate is 48kHz. When the real-time option is used, the ALLPASS1 signal is output.

2. DC output

The DC output is mostly a signal linked to the bar indicator, output from the D/A converter. The bar indicator has a refresh cycle of 100 ms, but the D/A converter has a refresh cycle of approximately 1.3 ms, which is sufficient for a 10 ms dynamic response. During dual measurement, the main signal is output.

When the octave filter option is used, the signal that has passed through the digital filter is output from the D/A converter. In this case, the sampling rate is 48kHz.

When reading memory data, the bar indicator will correspond to the read data, but the DC output will output the currently input signal. When the real-time option is used, the ALLPASS1 signal will be output, similar to the AC output.