1 This part of ISO 7507 specifies a calibration procedure for application to tanks above 8 m in diam-eter with cylindrical courses that are substantially vertical. It provides a method for determining the volumetric quantity contained within a tank at gauged liquid levels. The measurement required to determine the radius may be made internally (clause 8) or ex-ternally (clause 9). The external method is applicable only to tanks that are free of insulation.
2 Abnormally deformed, e.g. dented or non-circular, tanks are excluded from this part of ISO 7507.
3 This method is suitable for tilted tanks up to 3 % deviation from the vertical provided that a cor-rection is applied for the measured tilt as described in ISO 7507-1.