the calibration period of standard sand is one week, and the instrument for calibrating standard sand is mortar consistency meter.
The calibration steps of standard sand are as follows:
1. According to regulations, the grain size of finished sand is less than 4.75mm, so coarse crushing equipment+medium crushing equipment+sand making equipment should be selected when selecting crushing equipment, and the finished material can reach 4.75 mm.
2. According to the requirement of silt content, the materials coming out of the sand making machine can be washed away with the sand washing machine.
3. Suitable sand and gravel is also very important. You can choose river pebbles, limestone, granite, basalt and other materials, which have low mud content and are more suitable for building sand and gravel aggregates.