| abstract |
An indicator is disclosed, which is intended for detecting at least one test substance in a test medium, comprising a carrier and a reaction system consisting of at least a first reactant and a second reactant, applied separately on the carrier, said first reactant being intended to travel by diffusion to the second reactant through a parth in the carrier, soaked by the test medium, while reacting with the test substance. n The indicator is characterized in that the first reactant is applied within at least one limited locality, while the second reactant is applied within at least one locality, on a varying distance from the locality of the first reactant. |