The SPOT system reduces the potential risk associated with landing a floating roof when a large sludge bank is present. Mixer running patterns can also be monitored by using the system on a regular basis.
The equipment requires a 4″ internal diameter entry position into the crude. Therefore, roof legs, man-ways, vents, dip hatches, etc. could be used.
The survey is carried out with the tank full of oil, which eliminates the potential confined space problems that can be associated with working on floating roofs in their lowered position. Normally between one and three entry positions are all that is required to survey a tank with a diameter of up to 100m, preventing the need to remove large numbers of roof legs.