The measurement and control of levels of liquid and solid compounds have been present since the beginning of the petrochemical industry worldwide, with the advancement of time and technology these processes have become more exigent, demanding more accurate results with lower margin for the same. Taking into account the above, different types of industries have progressively incorporated in their control systems, leading technological inventories for recording measures, which over the years have evolved to reach their maximum potential seeking to deliver results more reliable. In the case of the Ecopetrol Refinery in Cartagena, there is a process called "Catalytic Cracking", which has the purpose of producing gasolines with a high commercial value due to their high demand in the market. Thus for the "Catalytic Cracking" process to be completed, it is essential to use as input a catalyst that is stored in two hoppers, one of which stores the "fresh or new catalyst" and another one stores the "spent catalyst" . In this context, if at any time you want to know the exact contents of the hopper remnants in order to replenish them, control the inventory of your purchase or finally dispose of what have become waste, is mandatory to make a measure not automated in the drums containing them, which is executed by operators manually using a tape measure which favors the exposure of the operators to the particulate material that makes up the catalytic substances. In view of the previous situation and the need to implement an automated online measurement to know exactly the inventories of the material, a project was carried out whose summary is explained below and shows the work of design and implementation of an automated measurement system in the hoppers Of catalyst in the Refinery Cracking plant in which radar sensors were used in line, which allowed to observe in the Distributed Control System (DCS) the tonnage they contained. Specifically, the work looked out for technological improvement in the measurement systems in the Refinery and in the systems of control of inputs in the Department of Catalytic Cracking, allowing to reduce the environmental impact, occupational impact and measurement error in order to obtain benefits for the health of the persons responsible for carrying out the measurements and the reliability of the measurement levels. The instrumentation system was designed and implemented by two radar sensors which are installed in the fresh and spent catalyst hoppers at the Cracking plant, which are responsible for recording the catalyst levels and then being sent to the Control System Distributed (DCS) for viewing. The level signals from the radars are managed by a controller which is responsible for storing them to have a record of trends and historical data of the levels, showing good results and the solution to the problem posed.