line ranger

steel tape

optical square

cross staff

straightening the links

removing one or more small circular rings

closing the joints of the rings if opened out

all of the above

±2 mm

±3 mm

±5 mm

±8 mm

is lighter than chain

is easier to handle

is practically inextensible and is not liable to kinks when in use

can be easily repaired in the field

centre of one handle to centre of other handle

outside of one handle to outside of other handle

outside of one handle to inside of other handle

inside of one handle to inside of other handle