Table 4. Distributed locations and types of foreign objects in the field

Types	Distance from exit nozzle			Remark
Types	0.5m	1.0m	1.5m	Remark
Stone or cement debris	A-2	A-2	A-1	Index
	c	b	a
	d	c	d
Metal pieces	Bolt, nut, washer
Wires	Wire pieces