Sound level meter - Frequently Asked Questions
Question number FAQ-1214
Number of files and data volume that can be saved on an SD card.
When the memory mode is set to "1TWAuto," one data entry records L p /L eq /L E /L MX /L MN /L pk, resulting in 86 bytes of data. In addition, 367 bytes of management information are included, for a total of 453 bytes used. In this case, although the data in one file is only 453 bytes, the memory usage is 16,384 bytes.
SD memory cards are managed by a file system. The smallest unit that makes up a single file is one cluster. The size of one cluster is 16384 bytes.
Whether you save 50 bytes of data or 16,000 bytes of data, the file size will still consume one cluster (16,384 bytes). When saving data exceeding 16,384 bytes, multiple clusters will be used depending on the size. The number of files that can be saved on an SD memory card, assuming the data from a single measurement fits within the size of one cluster, is as shown in the table below.
| SD memory card capacity | Number of files that can be saved after formatting (approximate) |
|---|---|
| 32 MB | 1893files |
| 64 MB | 3873files |
| 128 MB | 7678files |
| 256 MB | 15604files |
| 512 MB | 31244files |
| 1 GB | 60456files |
Depending on the measurement and memory mode, if the amount of measurement data exceeds one file, it will be saved using multiple clusters. However, even in this case, only one file will be created.
| Measurement & Storage Examples | Number of clusters used |
|---|---|
| If you measure L Aeq once and save it manually | 1 cluster |
| Using LA-05521/3 Octave Real-Time Analysis (optional), the L of real-time octave analysis eq and L x If the measurement time is 5 minutes and the total measurement time is 2 hours, it will be automatically saved. (24 data) (3TWL) x mode) | 2 clusters |
For information on the LA-0554's sound recording function, please refer to a separate FAQ.
Last updated: 2007-09-18