What does the level displayed in dBµV on the SONAPHONE Pocket mean?

The SONAPHONE Pocket displays the ultrasonic level in dBµV.

This is a logarithmic representation of the electrical signal voltage at the microphone input or probe connection.

The reference value is 1 µV (microvolt, RMS).

This means:

What does 0 dBµV mean?

0 dBµV does not mean that no signal is present.

At 0 dBµV, the measured input signal voltage is 1 µV.

A positive dBµV value indicates a signal voltage above 1 µV. A negative value indicates a signal voltage below 1 µV.

For this reason, the SONAPHONE Pocket may also display a negative level when only a low background signal is present.

Why is the scale logarithmic?

A logarithmic scale allows very small and very large signal values to be displayed compactly.

An increase of 20 dB corresponds to a tenfold increase in signal voltage:

• 0 dBµV = 1 µV
• 20 dBµV = 10 µV
• 40 dBµV = 100 µV

Even a change of only a few dB therefore represents a measurable change in the input signal.

Is dBµV the same as a sound pressure level in dB?

No.

On the SONAPHONE Pocket, dBµV refers to the electrical signal voltage generated by the connected probe or microphone.

The value must therefore not be treated as an acoustic sound pressure level in dB referenced to 20 µPa.

For comparative measurements with the SONAPHONE Pocket, the same probe, settings, and comparable measurement conditions should be used wherever possible.