The level indicators CRXI by the Italian company F.lli Giacomello are build in accordance with the Atex Directive (94/9/EC) for use precise and constinuous indication of the level of a liquid in a generic tank, placed in an environment where there is a continuous for a long period of time an explosive atmosphere consisting of a mixture with air or flammable substances in the form of gas, vapor or mist (zone 0 – ref. EN 60079-10).
What about their operation? The Floating houses within a toroidal magnet, whose field operates without physical contact, small reed switches located inside the tube.
The drive of these contacts allows the gradual setting or unsetting of the resistors, which are also placed inside the sliding tube, allowing the continuous reading of the liquid level.
The resistive signal thus generated is converted into a 4-20 mA signal manageable in a safe zone thanks to the use of a separation barrier.
The mounting of the level indicator must be in a vertical position. The float, each in its position, has to be distant from ferrous surfaces (tank walls, etc.) minimum 35 mm.
A gasket (flat or toroidal) guarantees from the escape of liquid through the fixing hole of the level switch.