Linear Measurement Instruments and their Permissible Error Range

[Azhar Shahzad 4]

1 - Pacing

Permissible error ≤ 1 feet in 20 feet.

2 - Chain

Permissible error ≤ 1 in 1000.

3 - Metallic Tape

Permissible error ≤ 1 in 1000.

4 - Steel Tape

This tape is made of steel alloy of very small co-efficient of thermal expansion.

Permissible error ≤ 1 in 1000.

5 - Invar Tape

This tape is made of very expensive steel alloy of almost negligible co-efficient of thermal expansion and is used for very precise linear measurements.

Permissible error ≤ 1 in 50,000.

6 - Techometry

Permissible error ≤ 1 in 50,000.

7 - Electronic Distance Meter

Permissible error ≤ 1 in 100,000.