KOBOLD rotating vane flow meters series DRH are used for measuring and monitoring low viscous liquids. Series DRH flow meters are working according the wellknown rotating vane principle. A magnet fitted in the vane and hermetically sealed from the medium transfers non-contacting the rotary motion to a Hall-effect sensor mounted in the housing. The sensor converts the rotary motion which is proportional to the flow to a frequency signal. A series-connected electronics unit converts the signal to an analogue output, limit contacts or display. This devices can be adapted to prevailing plant conditions with the 360° rotatable screw connections.