If a validator on a 10-km course finds 10,005 meters, for simplicity and to be on the safe side we have to assume that his is the best ride and add 5 meters. However, the assumption might not be true with the traditional measurement method unless the validator is able to wait to do his measurements until a time when temperature is steady or changing steadily. Validation is best done with the pressure-monitoring method which eliminates the affect of temperature on the measurement.