When installing the automatic waterer, make sure that the water pipes to the unit are below the frostline.
当安装饮水器时，务必确保水管到装置低于冻结线。
2
To prevent damage from repeated freeze-thaw cycles, the bottom of the foundation must be below the frostline.
为了防止反复冰冻解冻循环的损害，地基的底部必须在霜线以下（此处的土壤不受地表冰冻的影响）。
3
The experimental results indicated that the frost layer grew very slowly with the effect of ultrasound, and the frost layer composed by "frostline" was more inerratic.