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Distance Between Two
Points
Pacing
Chaining
Temperature
Standardisation
Catenary
Slope
Tension
Tachaeometry
Stadia System
Measurement of
Tacheometric Constants
Refraction and Curvature
Theodolite
Tachaeometry
Field Tachaeometry
Electronic Tachaeometry
Temperature
Most materials expand and contract with temperature change, and this effects taped distances. If a tape has stretched due to heat it will read shorter than it would at its normal (or standard) temperature.
The corrected length is computed as follows:
L = 1 + 1.c.Dt
For example, if;
| t = | 20°C (usual) |
| t = |
37°C (hot!) |
| l = | 79.984 |
| c = | 1.15 x 10-5m/°C |
then:
| L = | 79.984 + 79.984 x 1.15 x 10-5 x 17 |
| = | 80.000m |
So, if a distance of 79.984m was measured at this temperature, the actual distance would have been 80.000m. Conversely, if it was needed to lay out a line of 80.000m then a tape distance of 79.984 would be used.