Yeah, that sounds easy enough. Problem is the flow. Too small for such an "homemade sensor". Comercial sensors of this kind requires flows larger than 1liter/min, I think... That's a lot of fuel! Nuno. -- _/^\_ __ _____/\_________________________________oOOo__O-O__oOOo______/oo\____ /\/ / Nuno Filipe Freitas Pedrosa __ /..\__/ \ \/\ mailto:Nuno.Pedrosa@oen.siemens.de /`'\\__/-\ __ \/\ \ Tel. : 0049-89-72222342 \__/ \__//@@\ ___/ /\/_______________________________________________/OO\_..__\__/_ \/ \__/