Device for detecting a position of a printing material transported in a printing machine

A device for detecting at least one position of at least a part of a printing material while the printing material is transported in a printing machine, the device comprising:

• an optical sensor for establishing a distance between a printing machine component and the printing material;
• and
• a computer for temperature-compensating the distance established by said optical sensor;
• said computer saving an intensity pattern of said optical sensor on said computer, and said intensity pattern representing a measurement uninfluenced by external temperatures;
• said computer comparing an intensity pattern established by said optical sensor under thermal influences and said saved intensity pattern without thermal influence;
• and
• said computer calculating said thermal influence and compensating for said thermal influence in a computational way based on a deviation between said two patterns.