  A best practice guide for assembling and testing a simple and inexpensive
system feeding an optical fibre into a high pressure and temperature
environment is presented. A standard Swagelok type connector is tested together
with different ferrule materials and a PEEK capillary tube as feed-through. The
system proofed to seal an optical fibre during several pressure and temperature
cycling experiments up to 500 bar and 180{\deg}C.
