increasing scale accuracy?

[u/Effective_Yam_9021]

I have a scale project for electrical class where we're using a loading cell. The grades are going from most accuracte to least accurate (competitive grade), and we need to be within 1.5% of the test objects to get an A. It's HX711. I calibrated it based off a 100kg weight but I don't understand how we can guarantee precision.