i'm new on this field, i used to create something by sample, seems to be hard for me 
SD card is very important for stand alone logging device i think.
Storage is important for a logging device, but an SD-Card might not be a good choice- at least with a standard filesystem.
The issue is that if you're logging, every time you commit data you will be updating metadata (i.e. the directory and FATs in the case of a FAT-based filesystem) which are typically at the start of the storage device. Now my understanding is that an SD-Card /might/, depending on the vendor, go to some trouble to extend the longevity of the low blocks; however since there is no wear levelling they are likely to fail before the remainder of the device: and when that happens your data is lost.
I've got various thoughts on mitigation which I'd prefer not to discuss, but you might find something like
https://hackaday.com/2019/01/24/cool-tools-a-little-filesystem-that-keeps-your-bits-on-lock useful.
MarkMLl