This document summarizes the points of attention when applying pressure measurements with pressure transmitter assembled with diaphragm seals in urea plants. Its content is based on evaluating several troubleshoot cases in the industry. Pressure measurements with diaphragm seals are considered a very robust measurement solution to protect the pressure instrument from the often harsh process conditions. However, the diaphragm seal system needs to be engineered and installed properly. Firstly, this means selecting the best suitable diaphragm seal type and diaphragm size, suitable filling fluid to match temperature and withstand possible vacuum and the suitable material of the wetted parts of the diaphragm seal, to be best compatible / corrosion resistant with the process. Some transmitter manufacturers offer sizing calculation reports. One company provides online diaphragm seal sizing and selection tool, that helps to understand the impact of diaphragm seal type selection in combination with process conditions and installation and provides a total probably error of the complete system. This software is available at www.basecal.com, power by Badotherm, one of the leading diaphragm seal manufactures in the world.