Positive error: These errors make the measured length more than the actual length which results into wrong calculations by the Surveyor. Examples: ● The length of chain is shorter than the standard length due to bending of links, removal of connecting rings and knots in links. ● The temperature is lower than at which the tape was calibrated. ● Not applying sag correction. ● Sag takes place due to self weight of the chain. ● Incorrect alignment