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EODR: Electro optical distance ranging method (Internal) For Empty Tank


This method is based on the measurement of internal diameter of vertical cylindrical tanks having diameters equal to or greater then 5 meter by means of an electro optical distance ranging (EDOR) instrument and subsequent compilation of tank capacity tables.

Reference Standard: API Chapter 2.2 D 

This method is for Internal application only 

Like ORLM and OTM the method establishes diameters of all courses Procedure 

Establish a reference target on the bottom course and note the reference distance and reference angle 

Spherical coordinates are measured using distance ranging device (r, α, β) for each target point 

Tank profile is thus established from bottom to top 

The reference distance of the target and the reference angle of the target at the end are rechecked 

Using standard mathematical procedures, diameter of courses is computed 

With an on line computer, diameters can be determined instantaneously

Internal Measurements (for empty tanks)

Datum plate height, deadwood (manhole, pipes, beams, coils, etc.) roof structure, roof leg pin spaces are recorded. Floating roof weight and ladder weight for floating roof tanks are taken from existing reference to calculate volume deduction factors in density correction tables. Bottom calibration up to datum level and subsequently up to flush point is done with water flow meter.