A metal bellow seals the system from the medium to the measuring and display part. The movement transmission is done by force. A micro-switch arranged in the measuring part and a control lamp are activated. Corresponding switching processes are triggered by this micro-switch.
If the T-part of the DW-N device types is affected by calcification, debris or dirt, there is a message ‘no throughflow’. This means that it is virtually impossible for the system to stop in a position in which flow is indicated but where there is none.