‒ → Check uniform all-round pretension between panel seal -2- and body using a roughly 0.3 mm thick strip of cardboard (e.g. business card). It must be possible to run the strip of cardboard cleanly through between panel seat and body.
‒ In the event of insufficient pretension the panel seal can be forced apart with a wedge -1- or squeezed together if the pretension is excessive. Adjusting the panel seat involves removing the glass panel -3-.