Concrete mixing station weighing system how to be a problem, calibration weighing accuracy, our factory have sand aggregate weighing weighing system allowed error range + / – 2%, water permissible error range of plus or minus 2%, cement weighing allowed error range + / – 2% plus or minus 2%, admixture, fly ash weighing allowed error range weighing allowed error range + / – 1%, let’s take, for example, the sand and gravel aggregate said school known as example.