KROHNE DWM 1000-2000 EN - Manual (Page 3)

3
DWM Flow Meters and Switches
The DWM electromagnetic flow meters and switches are
designed to measure and monitor the flow rates of
e l e c t r i c a l l y c o n d u c t i v e l i q u i d s , p a s t e s a n d
s l u r r i e s
Versions
 DWM 1000 flow switch, 2-wire system.

DWM 2000 flow meter, 4-20 mA current output/readout.

DWM 2000 L (Long) for flow pipes of greater than 400m
diameter or open channels.

DWM 2000 IP68 for immersed applications.

DW M 2000 FT for food applications with
Tuchenhagen connection (detailed in a separate
instructions leaflet).
Special Features

Rugged design, IP55 protection, equivalent to NEMA 4
and 4X standards.

All wetted surfaces of ceramic, stainless steel and
platinum.

Compatible with process temperatures up to 150°C
(300°F), and ambient temperatures between - 25 à + 60°C

Suitable for operating pressures up to 25 bar (360psi).

No moving parts, maintenance free.

Electronic unit replaceable without interruption of flow.

Compatible for all pipelines with nominal diameter
(DN) 50mm
(2”).

Readout connection possible with handheld consoles
(DWM 2000 only).
Components of DWM 1000/2000
1 Connection Socket
2 Gasket
3 Sensor
4 Threaded Connection (1")
5 Earthing Cable
6 Earth Clamping Strap
7 Cable Entry Gland M20x1.5
8 Housing
9 Blanking Plug
10 Supply Terminals
11 Connection Chamber
12 Magnetic Coils and Electrode Contacts
13 Electronic Unit
14 Cover Screws
15 Cover With Fitted Gasket
Measuring Principle
If an electrical conductor moves through a magnetic field, a
voltage,U, is induced in the conductor. In the case of the
DWM, the liquid in the flow pipe is the electrical conductor.
In the diagram below, the DWM creates the magnetic field,
B, perpendicular to the direction of flow. The induced volta-
ge U is directly proportional to the local flow velocity v.
U = k x B x v x D k - Instrument constant
B - Strength of magnetic field
v - Flow velocity
D - Electrode spacing
Voltage U is tapped off from the electrodes, neutral and
ground electrode (connection socket)
DWM 1000 Flow Switch - Voltage U is converted into a
switching signal with adjustable switching point.
DWM 2000 Flow Meter - Voltage U is converted into a flow-
proportional output signal current between 4-20 mA (load
independant).