De Gidts & Feldman received a large commission by a Dutch oil refinery. It concerns the Honeywell Smartline ST800 pressure and differential pressure transmitters, the membranes of which are coated with pure gold.
Hydrogen diffusion prevention
This may sound quite special, but it is more common than you would think. The membranes are made with gold to prevent hydrogen atoms from being able to diffuse through the membranes of the transmitters during the cracking process. These membranes are normally of high-quality steels such as stainless steel 316 or Hastelloy C-276, but this is not sufficient for this special application.
Stainless steel 316 with 16-micron gold
In a very precise electrolysis process, the measuring cells of the transmitters are covered with a gold plating of approximately 16 microns, which ensures reliable measurements for many years. Of all transmitters available on the market, the Honeywell Smartline is best suited for applying a gold coating. The Honeywell membranes are standard made of stainless steel 316. Gold adheres to stainless steel much better than to Hastelloy C-276, which is used as membrane material by many other manufacturers.