Compared with conventional X-ray images, the Rapiscan Multi-Energy System provides additional information about the chemical composition of the inspected items.

The Multi-Energy System distinguishes between materials according to their atomic weight (organic / inorganic), and uses different colours to classify screened objects. The classification is carried out by a real time calculation based on the absorption factors of materials, measured as a function of the radiation hardness. The colours are classified into three main groups:

Group 1 - Orange

Organic substances composed of light chemical elements which have an atomic weight of under ten (irrespective of their molecular structure) are displayed in orange. The most important elements in this category are Hydrogen, Carbon, Nitrogen, and Oxygen. Most explosives are made up of a combination of these elements. Explosives such as Nitro-Glycerin and Semtex belong to this group. Materials such as drugs, paper, wood, water, and plastics will also be displayed in orange.

Group 2 - Green

Objects of a medium heavy element such as aluminium, are displayed in green. This also applies to overlapping areas of organic and inorganic substances. This group is termed the "mixed" group.

Group 3 - Blue

This group is composed of inorganic substances such as Steel, Zinc, Tin, Copper etc.

Where materials exceed their atomic weight classification by density, they will be displayed in BLACK. This feature is unique to the Rapiscan Multi-Energy System.

If different materials overlap, the color depends on the material which contributes most to the absorption of the radiation. This means that metal areas of medium thickness do not affect the ability to recognize plastics. The intensity of the displayed color is a measure of the thickness of the material.

The Rapiscan Multi-Energy method retains good penetration and high resolution, providing the operator with more information and, accordingly, a greater assessment of the contents of screened items.

ECIL - Rapiscan Enhanced performance x-Ray (EPX)

EPX is an option within the 500 series which has been created to give operators greater materials discrimination together with the opportunity to specifically identify Explosive, Narcotics, Gold and Currency.

Conventional X-Ray systems will display organic substance in Orange, however, while explosives and narcotics fall within  the organic group , many other items such as paper, plastic, rubber, leather and soap are also organic and would be displayed in organic. ECIL- RAPISCAN EPX provides the solution by identifying substance having the specific characteristics of explosives or narcotics, by displaying them in RED thus enabling much more rapid and consistent detection capability. Gold or currency may also be identified and displayed in RED using EPX.