Magnetic Inductive Flow Sensor SIKA VMI 20

Type: VMI20ASS00YGI000

VMI20-Y, SP-MID0467

Drawing MID-0467

Measuring tube PEEK

O-rings EPDM

G 1 external thread, stainless steel

DN 20

PN 16

Media temperature: +5 ... + 90 ° C

Ambient temperature: min. + 5 ° C, max. +40 ... + 70 ° C. depending on the medium temperature, see data sheet

Measuring range 5 ... 250 l / min

5-pin connector M12x1. Pin 1: Power supply 24 VDC ± 10%. Pin 2: Analog output flow 4 ... 20 mA corresponding to 0 ... 250 l / min. Pin 3: GND. Pin 4: Frequency output (push-pull), 100 pulses / liter. Pin 5: do not connect. including factory certificate.

 

Function

The magnetic inductive flow sensor operates on the induction principle, d. h., by the movement of a conductor in a magnetic field, a DC voltage is generated: The measuring tube of the VMI is located in a magnetic field (B). An electrically conductive liquid (Q) flows through the measuring tube. Here are the positive and negative Charge carrier deflected opposite. The result is a voltage perpendicular to the magnetic field, which is tapped by the two electrodes. The induced voltage is proportional to the mean Flow velocity of the liquid. The electronics of the VMI convert the induced voltage into a flow-proportional frequency signal.

 

The VMI can in principle be installed at any point in the pipeline. Straight pipe sections are to be preferred. • Installation can be carried out in horizontal as well as in vertical pipelines. The flow sensor is only suitable for use in completely filled pipes. • Due to the principle, magnetically inductive flow sensors are largely independent of the flow profile. A calming section is not mandatory. However, to achieve the highest possible measurement accuracy, straight inlet and outlet sections of the corresponding nominal diameter (DN) should be used. The inlet section should be at least 10 x DN, the outlet pipe 5 x DN long. • The inlet and outlet sections, as well as the seals, must have the same or a slightly larger inside diameter than the measuring tube in order to achieve the specified accuracy.