My first experiment: pouring 500ml water (a new measuring cup) into a mixing bowl, the scale showed less than 400 grams. I was not sure at the moment whether the scale or the measuring cup was wrong although I knew deep down it's probably the scale.
In order to trust this adorable little scale I did a series of really dorky experiments: measuring 30 ml of water from an old little measuring cup and it was accurate; measuring a unopened package of food (1lb) and it was about right; and putting 500ml water bottles onto the scale one by one and it starts to break after two bottles.
The final experiment was lethal. I put one 500 ml bottle of water to north, west, south, east of the measuring disc and the results ranged from 330g - 540g. In order to exclude the factor of unevenness of table, I turned the scale and the results repeated.
I am kind of sad it didn't work out. I also wonder if I didn't do everything ahead and just used it assuming it's accurate, maybe I will still make all the great dishes.