Because of the possible precipitation and deposition of organic waxes while the production and transport of paraffinic crude oils, plugging and pressure losses can occur, which cause longer workovers and additional costs. Therefore it is necessary to investigate this topic and to develop solutions. For this purpose OMV Exploration and Productions purchased a wax-loop apparatus. Due to the better adjustability to certain applications, this apparatus should partly or completely replace former measurement methods of the effectiveness of wax inhibitors, like cold finger tests or rheometer measurements. The aim of this master thesis was to place the new device into operation, to optimize the test parameters and to test chemical wax inhibitors with certain parameters and crude oils. Further a working instruction was gathered, to alleviate future measurements. The second part of this master thesis deals with a scale loop apparatus, that was also purchased shortly before and which is used to test chemical scale inhibitors. Similar to the problems with paraffinic crude oils, anorganic deposits can be built from reservoir or injection water due to changing environment conditions. The consequences are also possible plugging of tubes or an increase in the pressure drop. This apparatus had to be placed into operation too and test parameters had to be optimized. After that different scale inhibitors were tested. On the basis of this a working instruction was written. Another part of the work is to identify weak points of the buildup of the two apparatus, to determine operational boundaries and to suggest improvements.