Sources of Error in Egg Specific Gravity Measurements by the Flotation Method

Experiments were conducted to examine the sources of error in the measurement of egg specific gravity (S.G.) by flotation in saline solutions to estimate shell quality. The sources were: the effect of temperature on the solution S.G.; errors in calibration and reading hydrometers; hairline cracks in the shell; cooling of the solutions by stored eggs; and the fact that hydrometers are calibrated at 60° F. (15.6° C.) and used at room temperature. Results indicated that the errors are not accumulative but that significant errors (up to 0.006) can be introduced into the readings. Changes in procedure and equipment are recommended to reduce the errors.