A.1;5~10 B.2;20~30 C.3;10~20 D.4;相平
A.5~10;管路相對較長 B.10~20;就地測點比較分散 C.20~30;管路相對較短 D.30~40;單獨一根儀表管
A.120~150mm B.70~100mm C.150~250mm D.100~150mm