in the CSV file the RAW_TP9 means raw EEG amplitude? the Alpha_TP9 means alpha wave power or raw alpha amplitude?
You can find the CSV specs on the Muse Monitor website here.
RAW_TP9 is microvolts on the left ear, Alpha_TP9 is the Alpha brainwave power spectral density on the left ear.
why is the file size same when I used the sampling rate of 1 sec and constant during a same period?
The compressed ZIP file may be roughly the same size, but if you unzip and look at the CSV it will be much larger.