The control technique with penetrating liquids is based on the “wetting/capillarity” properties of particular liquids and the method is used to detect surface defects on both metallic and non-metallic materials. Schematically, it works by applying a liquid to the surface under examination which penetrate by capillarity inside the emerging discontinuities; and, after removing the excess liquid from the surface itself, the fraction introduced into the discontinuities is highlighted by a particular absorbent agent, thus giving rise to a visible indication corresponding to the surface defect sought.

The indications obtained can be observed in white light or with Wood’s light (UV radiation) depending on whether they are used, respectively, penetrating liquids with COLOR CONTRAST or FLUORESCENT. The latter, by virtue of the resulting high luminous contrast, guarantee a higher detection sensitivity than can be obtained with colour contrast penetrants.

Differently from magnetic particles testing, where the machine is often designed considering the piece that has to be inspected, Penetrant Testing is recommended to be the most flexible and malleable one and it offers a single system thought for an extended range of items. These systems are divided into three large families:


Most of the time, tank liquid penetrant systems include the immersion of the examined items into the liquid penetrant used. The full immersion of the piece ensures the liquid application on the 100% of the surfaces. In this kind of systems, the following pre-washing operations, the emulsification (if necessary), the final washing, the drying and the application of the developer can occur or not occur into the tanks according to the method applied.

CGM CIGIEMME S.p.A. provides its customers with a full range of tank systems, starting from very simple manual systems (MODULAR), arriving at totally automated systems where the pieces follow their cycle moved by automatic manipulators. The systems are designed and constructed entirely according to the available space and the inspection cycles to be followed. This type of plant can very often work with different penetrant levels (S1, S2, S3 and S4) managing the different work cycles with ease.

The most modern applications CGM CIGIEMME S.p.A. they include the application of penetrant and developer by means of electrostatic guns also for tanks systems. This is to minimize the consumption of the products, with an eye towards the environment.

CGM CIGIEMME S.P.A. systems are CE marked and realized in accordance with the rules in force.



Cabin penetrating liquid systems involve the application of penetrating liquid on the surface of the piece being examined by spraying inside cabins equipped with an optimal suction system. Spraying can be a standard spraying or, more modern, electrostatic method.

This type of plant is usually used for medium-large sized pieces, for which the immersion of the piece would become difficult to manage. Given their great flexibility, they can also be used when the dimensional range of the pieces is wide and varied.

The handling of the pieces and the application of the products can be manual or totally automatic, depending mainly on the required productivity. CGM CIGIEMME S.p.A. has developed fully automatic booth lines, where the only manual operations are the loading / unloading of parts and the inspection.

Work cabins can have different dimensions depending on the pieces to be processed. The number of cabins may vary depending on the space available and the cycles required. The implants allow the use of different penetrant sensitivities (S2, S3 and S4).

CGM CIGIEMME S.P.A. systems are CE marked and realized in accordance with the rules in force.



The mixed liquid penetrating systems for tanks and cabins have been developed by CGM CIGIEMME S.p.A to provide the customer with the high flexibility characteristic of booth systems and the high process control, typical of tank systems.

In this type of system, the application of the penetrant in the cabin with standard or electrostatic spraying is envisaged, while the application of the emulsifier and the subsequent important Stop-Off phase is managed in tanks, so as to have total control of the times in these two fundamental phases of the process. Washing, drying, application of the developer and inspection are executed inside the cabins.

Mixed cabin-tanks systems are widely used in the Aerospace / Energy sector where great flexibility and absolute control of the process phases is required.

The CGM plants CIGIEMME S.p.A. they are CE marked and made according to the regulations in force.