What do the level values displayed by the SONAPHONE mean?

The SONAPHONE can display different level values. These values describe different characteristics of the measured ultrasonic signal:

• L – instantaneous level:
  Displays the level currently being measured.
• LF – smoothed instantaneous level:
  The instantaneous level is smoothed over time. As a result, brief fluctuations have less influence on the displayed value.
• Lpk – peak level:
  Displays the highest short-duration peak of the signal. This value is particularly suitable for detecting impulsive events.
• Leq – equivalent continuous sound level:
  Describes the average sound energy over the measurement period. Leq is suitable, for example, for comparative and trend measurements.
• Lmin – minimum instantaneous level:
  Displays the lowest instantaneous level recorded during the measurement.
• Lmax – maximum instantaneous level:
  Displays the highest instantaneous level recorded during the measurement.
• CREST factor:
  Describes the ratio between the peak value and the root mean square value of the signal. A high CREST factor indicates pronounced signal peaks or impulsive events.

The level values that are suitable for a test depend on the respective application. For recurring measurements, the same settings, sensors, and level values should always be used to ensure that the results remain comparable.