Class 1 Sound Level Meter NL-53/Class 2 Sound Level Meter NL-43 with Extended Function Program NX-43EX Instruction Manual Operation Guide - Measurement

10.7 File organization

^* The extension .rnd is a store data file.
^* The extension .rnh is a header file where settings etc. are recorded (Auto only).
^* For L_eq store, files are divided every 60,000 stores (every storing 60,000 calculation results).
^* For L_p store, files are divided every hour, and folders are divided every 1,000 files.
^* NL-53 has the same file structure.