Tapes used in surveying measurements are standardized at a specific temperature. Since measurements are taken at temperatures which may vary significantly from the temperature at which the tape was standardized, tapes may be either “too long” or “too short”. Temperature variation is a source of variable systematic error and is in direct proportion to the number of tape length measured. (La Putt, Elementary Surveying 3rd edition p. 93)
The correction applied to the length of the tape due to change in temperature is given by the formula
