DOG-5 Oscillation Flowmeter

The KOBOLD flowmeter DOG-5 is used for non-contact flow measurement of low viscosity liquids. The medium flows through an orifice in a tube and side bypass bores. The dynamic pressure at the orifice causes part of the liquid to flow through the bypass. The division ratio remains constant over the whole measuring range.

The bypass channel contains the Oscillator – the  measuring cell itself. When the medium flows through the measuring cell, a liquid column oscillates in a U-shaped channel mounted to the left and right. 

This oscillation frequency is  proportional to the flow velocity. A chamber with a hollow ball is situated over this channel. It is connected with the lower channel by two bore holes.

The oscillation of the liquid column is thus transferred to the ball, which in turn moves back and forth with the same frequency. The ball movement is sensed by an initiator. An electrical alternating signal is generated that is  displayed in the series connected electronics.