Array size and available RAM?

Env: SES, nrf52 DK, Linux

Hi

I need to define a buffer (array of structure) in order to buffer readings. If i have more RAM I should create a bigger buffer if I have few RAM I need to create a short buffer.

My problem is that I can not get the available RAM.

When I rebuild program using SES it shows 2 charts with FLASH and RAM measurements, However, If I create a

unsigned char arr[1000];

as a global var or as a main function var the measurement is always the same after compilation. Why doesnt SES take into account the RAM occupied by new array?

Thanks

Alex