This describes the corrosion of an adhesive tape to another material. To organise the measurement of the corrosion, the adhesive tape is tested with special conditions. The adhesive tape is adhered to a testing film made of brass and then direct current voltage, heat and humidity interact at the same. A specific value is assigned to the material as a measure for the corrosion of the testing film. The positive pole film gets values from A (no change) and AN, A/B to B (intensive red colouring) and the negative pole film values from 1 (no change) to 1.2,1.4 … 2, 3 up to 4 (significant colouring). Factors up to 1.4 are not count as corrosive in the electro-technics.