Table saw - Lo-Tech blade alignment

[niki]

Good day

I don't have all those "Hi-tech" instruments to check the blade alignment so I "invented" a "Lo-tech" method.

The straight edge must be not only straight but also consistent in width all along (check with caliper).

Instead of the 8"~9" distance of the blade, I'm using a 30" distance (the table length) to measure the deviation and by that, multiplying the mistake and I can adjust the blade parallel to the miter slot much more accurately.

Regards
niki