Load Cell - 10kg, Straight Bar (TAL220) Accuracy??

I followed the instructions here… https://circuits4you.com/2016/11/25/hx711-arduino-load-cell/....to hook up the load cell, amp and Arduino 2560. Everything works like a charm. How do you know the accuracy of what your reading in the “serial window” when the Arduino IDE is run?? See attached. It says Reading 0.0 kg. I did as instructed and changed lbs to kg in the code but isn’t there some scaling that has to be done also to go from lbs to kg?? BWT I want to measure grams. So its that just a matter of changing my kg to grams ???Is the "Reading:0.0 kg… " just a number? And I assign units??

There is a field called Metrology or in common terms precision measurement and calibration. To calibrate you need an accurate weight depending on how accurate you want bag of sugar accuracy or an ounce of gold thing. And you can fine tune Arduino readings. If you are planning to measure grams get a load cell closer to the max you want to measure or additional ones for each range. Avoid applying a load greater than its rating or it will become damaged. There is a special tester for calibrating force gauges.