第一、听声音。将仿大理石uv板立起来,用手敲击板材,声音越清脆证明密度越高,品质就越好,如果声音低沉,证明密度差。 First, listen to the voice. To put up copy marble uv board, tap on a plate with the hand, voice ringing prove density higher and higher, the quality is better, if the voice, prove that the density