sound level meter Frequently Asked Questions
Question number FAQ-1214
Number of files and data amount that can be saved on an SD card.
In the case where the memory mode is set to "1TWAuto", 1 data is recorded as L p /L eq /L E /L MX /L MN /L pk, with a data byte size of 86 bytes, plus an additional 367 bytes of management information, totaling 453 bytes used. In this case, while there is only 453 bytes of data in one file, the memory usage amounts to 16384 bytes.
SD memory cards are managed by a file system. The smallest unit that constitutes a single file is one cluster. The size of one cluster is 16,384 bytes.
Whether you save 50 bytes of data or 16,000 bytes of data, it will consume one cluster (16,384 bytes) in terms of file size. If you save data exceeding 16,384 bytes, multiple clusters will be used according to the size. The number of files that can be stored on an SD memory card will be as shown in the next table, provided that the data from a single measurement fits within the size of one cluster.
| SD memory card capacity | Number of files that can be saved after formatting (overview) |
|---|---|
| 32 MB | 1893files |
| 64 MB | 3873files |
| 128 MB | 7678files |
| 256 MB | 15604files |
| 512 MB | 31244files |
| 1 GB | 60456files |
In measurement and memory mode, when the amount of measurement data exceeds one file, it is saved using multiple clusters. However, even in this case, only one file is created.
| Measurement & Storage Example | Number of clusters used |
|---|---|
| If L Aeq is measured once and saved manually | 1 cluster |
| Using the LA-05521/3 Octave Real-Time Analysis (optional), if the L eq and L x of real-time octave analysis are measured with a measurement time of 5 minutes and an overall measurement time of 2 hours, and automatically saved (24 data points) (3TWL x mode) | 2 clusters |
For information about the LA-0554 sound recording function, please refer to a different FAQ.
Last updated date: 2007-09-18