Thanks everyone for your reactions to my doubts.I don't have the device--I should have at least looked for a photo of it before commenting, but ... in any case, I fully agree with Klaus's remarks about possible liquid propellant emissions from those common clean air pressure cans: I now use a Giotto "Q.ball" large squeeze-bulb, which of course does not put out high pressure air like a can, but mostly does the job. On Sat, Apr 24, 2010 at 7:17 PM, Vladimir Gajic <vgajic67@xxxxxxxxxxxxxx> wrote: > Agree with that. It's risky if you spray at a short distance. > > Regards > Vladimir > > > > -- Gesendet von meinem Palm Pre > ________________________________ > Klaus Karcher <lists@xxxxxxxxxxxxxxxxx> schrieb am 24.04.2010 20:21: > > Ernst Dinkla wrote: >> The cone will be taken off the instrument before the cleaning. It is a >> simple part with a 0.55mm selected white float glass disc glued in at >> the wide side. One expects that the UV cut version will have the filter >> glass there. I guess Vladimir uses one of the clean air pressurised cans >> to blow the dust out, you wouldn't like to use 8 bar air with oil mist >> for that purpose. > > I use a very thin brush to clean the inner side of the cone -- works > like a charm. I've had bad experience of compressed air in cans: they > can spray propellant drops that leave stains behind on optical surfaces. > > Klaus > >