Kobold DOT Turbine Wheel Flowmeter/Monitor

Kobold DOT Turbine Wheel Flowmeter/Monitor 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.

Kobold DOT Turbine Wheel Flowmeter/Monitor

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.

Kobold DOT Applications

Chemical and allied products
Pharmaceuticals
Deionised water
Fuel additives
Petrochemicals
Plastics and hydraulics
Water conditioning
Other low viscous fluids

Design

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 meters 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.

Kobold DOT Specifications

Sizes: 15mm...300mm (½"...12"ANSI, DN15...DN300), bigger on request (see model no. designation for information on available sizes)
Linearity at 1cP: ±0.5% of reading, (±0.2% when utilising the linearisation feature of electronic type Z3)
Repeatability: ±0.02...0.05% under steady flow conditions
Max. pressure: threaded connections: 250 bar
flange connections: corresponding to flange specifications
Medium temperature: -20...+120ºC(ambient temperature max. +80°C)
Pressure drop: approximately 0.28 bar at maximum flow (SG = 1.0, Vis. = 1mm²/s)
Supply voltage: see electronics of datasheet
Electronic features: see comparison table of datasheet
Flanges: according to DIN2501 or ASME B16.5 (optional)

Materials

Housing: stainless steel 1.4401 (316 SS)
Flanges: stainless steel 1.4401 (316 SS) or carbon steel A106
Rotor: SS 430 (up to DOT-xx15), SS ANC 21 (Duplex stainless steel, for bigger sizes)
Bearing support: stainless steel 1.4401 (316 SS)
Bearings: tungsten carbide (shaft, bush, thrust plate)

Output

Preamplifier: Inductive sensor in option »F4S« is a turbine wheel sensor with integrated preamplifier. Specially designed for turbine flowmeters, the sensor provides amplified output on 3 wire.
Transmission distance: max. 500 m
Housing: stainless steel
Connector: MS acc. to MIL-DTL-5015 including a mating plug with 3 x soldering pins
Power supply: 12-24 VDC
Pulse output: NPN, max. 25 mA
Others: see relevant electronics datasheets ZOK/ZOE
Protection: IP55 (with option »F4S«) IP66/67 (with integrated electronic ZOK/ZOE)