More than 10 MB/s SD card for high speed data transfer is necessary.
In addition, do not mix the normal measurement data and sound recording data (WAV format) in one SD card.

When the data is stored in the above state, small free spaces are made after deleting the numerical data. The WAV data is inputted in this small free space intermittently, and it might be the storage error.
We recommend you to format the SD card before the sound recording.

• When you use the SD card for high speed transfer for the first time, format it in the menu of the sound level meter.

Recommended SD card (High speed type, operation is confirmed)