When the memory mode is set as "1TWAuto", one data is recorded in each unit of Lp/Leq/LE/LMX/LMN/Lpk and the number of data bytes is 86. 367 bytes is added for management data, so 453 bytes of memory are used in total. In this case, the data for one file is only 453 bytes, but the 16384 bytes of memory is consumed.
SD memory card is managed in the file system. Minimum unit which constitutes one file is one cluster. The size of one cluster is 16384 bytes.
One cluster (16384 bytes) is consumed regardless of the size of data. (Same amount of bytes are consumed even if the stored data is 50 bytes or 16000 bytes.) When stored data is more than 16384 bytes, multiple clusters are used according to the size of the data. When a single measurement data is within the size of one cluster, the storable file number in the SD card is as follows.
| Capacity of SD memory card | Storable file number after formatting |
|---|---|
| 32 MB | 1893 files |
| 64 MB | 3873 files |
| 128 MB | 7678 files |
| 256 MB | 15604 files |
| 512 MB | 31244 files |
| 1 GB | 60456 files |
Multiple clusters are used for storage when the measurement data amount exceeds one file due to the measurement and memory modes. Even in this case, only one file will be made.
| Examples of measurement and storage | Using cluster number |
|---|---|
| When manual storage after single measurement of LAeq. | 1 cluster |
| When the LA-0552 1/3 real-time octave analysis (option) is used and automatically stored the data of Leq and LX of the real time octave in the setting of Measurement Time of 5 minutes and Total Time of 24 hours. (24 data) (3TWLx mode) | 2 clusters |
For the LA-0554 Sound recording function, please refer to another FAQ.
Revised:2007.09.18
