The fl ow indicator model UFJ for liquids and gases operates on the suspended fl oat principle; i.e. the installation position is vertical and the direction of fl ow is from bottom to top. The instrument consists of a measuring tube in which a section around the set value is cut out. It has a marking in its slot comprising of a set value switching point and ranging from approximately -1 % ... +5 %, whereby the fl oat indicates the presence of fl ow.