Due to the extreme corrosive environment, all wetted parts are made of Monel 400. In this construction, Badotherm uses its USL diaphragm seal type with the lower part in Monel 400, but with welded flush valves and full penetrant welded welding neck flanges. Off course, all are duly certified. The Honeywell transmitter is a STD820, which is connected with the diaphragm seal by means of a full welded construction. Further, for increased chemical resistance and to prevent hydrogen permeation, there is a 40-micron thick layer of 24 CRT gold applied. This application, specially made for these hard circumstances, has a proven track record for SAPREF.