Control valves

Level indicators

Page 5 of 8

Potentiometer transmitter characteristics

A potentiometer is placed in the vertical weather-proof tube

outside the level indicator.

The total resistance of a known value is measured at the ends of

this potentiometer.

The float, following the liquid level trend, activates the potentiometer’s

reed contact chain through its own magnetic field, locally closing

the signal.

The total value of the resistance is measured 100% at its maximum

level and 0% at its minimum level.

The end poles of the potentiometer are connected to a converter

that transforms the input value into Ohm and the output into mA.

5 mm

Reading resolution available

10 mm

20 mm

Resistance input

1 k ÷ 100 k Ohm

Converter's housings

Converter types

Colima Visco and Viscorol Magnetic level indicators

TI-P329-01 CH Issue 1

Housing for safe area

Weather-proof IP65, plastic.

Housing for safe area, low / high temperature

Special type suitable to low temperatures or

installation in high

concentration saline environments and for use

in the food industry.

Entirely in stainless steel.

Protection degree IP67.

On request IP68.

Up to two cable entrances.

Housing for hazardous area, ATEX certified

ATEX certified II 1/2 G EEx d IIC T6, T5

resp. T4 for use in hazardous areas.

In pressure die-cast aluminium with a

polyamide paint.

Protection degree IP67.

Up to two cable entrances.

Converter for safe area

Field set using two trimmers

[for the Z (zero) gauging and G

(gain) gauging],

without resorting to

interconnecting systems.

Converter for inbuilt safe area

Field set using two trimmers

[for the Z (zero) gauging and

G (gain) gauging], without

resorting to interconnecting

systems.

Converter HART

®

protocol

Converter regulated with an

interconnection cable.

Resistance input

1 k ÷ 100 k Ohm

Current output

4÷20 mA

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4.9.6