Liquid level instrumentation in volume calibration

The technique of pressure head measurement for determining liquid levels in tanks has been used for the intercomparison of commercially available electromanometers with themselves and a sight glass. In addition to obtaining intercomparison information, the high precision of these devices coupled with that of volumetric transfer techniques demonstrates the applicability of the calibration method in determining departures of the actual tank geometry from that of a model straight walled geometry. It is shown that the calibration of the volume-to-height relationship of a 3,300 liter tank may be accomplished with an uncertainty in this relationship of approx. 4 parts in 10,000.