Metric chains — link density: For a standard metric survey chain used in basic chaining, how many links are there per metre length of the chain?

Introduction / Context:
Chains historically came in various lengths and link counts. In metric surveying practice, the commonly used metric chain is 20 m long and consists of 100 links connected by rings. Understanding link density (links per metre) aids quick conversions, error checks, and recognizing whether a chain is metric or otherwise in the field.

Given Data / Assumptions:

• Standard metric chain length = 20 m.
• Number of links in the chain = 100.
• Uniform link distribution along the chain.

Concept / Approach:
Links per metre equals total links divided by total metres. With 100 links in 20 m, the density is 100 / 20 = 5 links per metre. Each link is therefore 0.2 m (20 cm) long, not counting the small rings between links which are accounted for in the standardized total length of the chain.

Step-by-Step Solution:

Verification / Alternative check:
Contrast with Gunter’s chain (66 ft with 100 links) used in imperial systems; its link length differs. The metric chain’s simple 5 links per metre makes mental arithmetic straightforward.

Why Other Options Are Wrong:

• 2, 8, 10, 20 links/m do not match the 100-links-in-20-m specification of the standard metric chain.

Common Pitfalls:
Confusing the 30 m metric tape or chain (which still may have 100 links, yielding 3.33 links/m) with the standard 20 m metric chain; always confirm chain type before calculations.

Final Answer:
5