Test Media System

Classification of PT consumables

A combination of penetrant, remover and developer is referred to as a product family for penetrant testing. The following types are distinguished:


I: Fluorescent Penetrant Testing
II: Colour Contrast Penetrant Testing
III: Fluorescent Colour Contrast Penetrant Testing


A: Water
B: Lipophilic Emulsifier
C: Solvents
D: Hydrophilic Emulsifier
E: Water and Solvents


a: Dry Developer
b: Wet Developer on water basis, water soluble
c: Wet Developer on water basis, suspended
d: Wet Developer on solvent basis
e: Wet Developer on water or solvent basis (for special application)

Colour contrast or fluorescent penetrant

Fluorescent penetrants are preferably used for static series testing. If testing takes place in daylight conditions, colour contrast penetrants offer advantages, e.g. red indications. For the use at randomly changing locations, penetrants are also offered as spray cans. In any case you have to take care for the different sensitivity of the systems.

Selection of remover

Water is used for most PT purposes as penetrant remover. For special requirements emulsifiers can be used, e.g. to avoid strictly overwashing.

Developer Systems

Geometry and the amount of pieces to be tested are factors for the type of developer to be used. For colour contrast penetrant testing, which is mainly done under means of aerosol spray cans, quick drying wet developer based on solvents are commonly used. For series testing with fluorescent penetrants dry developer or water based wet developers are more convenient.

Delivery form

Penetrants are offered generally as ready to use product in order to eliminating errors of wrong mixture concentrations, which would have an important effect to the system sensitivity. Wet developers are mostly offered as concentrate for dilution.