The turbine flowmeter model DOT consists of a helically shaped turbine rotor supported in two tungsten carbide bearings, the rotor being solid ferritic stainless steel of a grade compatible with the metered liquid, all contained within a housing of non-magnetic stainless steel. A pick off coil having a permanent magnet core is mounted in the housing adjacent to the rotor blade tips such that a magnetic circuit is set up via the rotor blades (Fig.1).
Rotation of the rotor varies the reluctance of this magnetic circuit and the flux changes induce a small voltage in the coil, the frequency of which is directly proportional to the rotor speed and therefore proportional to the volumetric flow rate. The effects of increasing viscosity reduce the linear flow range and shifts the k-factor. Further, the effect of viscosity depends on the frequency (RPM of rotors). Therefore, smaller the meter, higher is the effect of viscosity on the linearity curve.
The DOT is a highly accurate, reliable and robust turbine meter used to measure the flow of clean low viscosity liquids.
Stainless steel construction with tungsten carbide bearings provides long life with a wide range of aggressive and non-lubricating liquids in petrochemical and general industrial applications.
The basic meter is available with a pre-amplified square wave output. These meter have MS (military style) plug/socket for the pulse output connection.
Alternatively the meter is supplied fitted with integral instruments. These may include e.g dual totaliser, rate counter Z3/ZE/ZB or dosing unit.
The electronics are identical to the series ZOK and ZOE, ATEX certification is not available. For further information please see the operation manual of ZOK and ZOE.