Ex-sensors

The sensors of the 46B Ex and 55 Ex series comply with category 3 and have been developed especially for zone 2 ("Gas-Ex") in protection type nA according to EN 60079-15:2005 and for zone 22 ("Dust-Ex") in protection type td according to EN 61241-1:2004. They may be used with conducting and non-conducting dust.

The sensors are accommodated inside a metal casing for protection against mechanical damage. This ensures that even the highest knocking test demands up to 7 joules are safely complied with.

These are designed either as a single-beam light barrier, as a reflection light barrier or as a reflection light button, and can detect objects reliably at distances between 300 mm and 12 m. The intrinsically safe ATEX sensors communicate the switching signals by way of the NAMUR interface to the VS 403 isolating switching amplifiers. Sensors of this series may be used in zones 1 and 2 in areas where there are potentially explosive gases and dust.

The VS 403 isolating switching amplifier makes it possible to effect an intrinsically safe circuit for the sensors of the ‘92’ series. The sensors are supplied with power and the switching signals communicated by way of the NAMUR interface. This isolating switching amplifier, which is certified in keeping with the most recent ATEX directives, is obtainable either with a 24 V power supply and relay/transistor output, or with an AC power supply of 110 to 240 V and relay output.

For setting up the intrinsically safe circuit, Leuze electronic also offers blue cables with M12 circular plugs to connect the sensor to the isolating switching amplifier.

The sensors of the 96 series were specially developed for device category 3, Ex zones 2 and 22.

All function principles, such as throughbeam photoelectric sensors, retro-reflective photoelectric sensors and diffuse reflection light scanners, are available in the series. To meet the stricter standards requirements of EN 60079-15:2005 and EN 61241-1:2004 with respect to impact resistance, the devices of the 96 series have also been equipped with an additional protective housing made of metal.

• Interlock guard K-V M12-Ex, 50109217 (prevents unintended disconnection of connectors)
  
  
• Cable for the connection of intrinsically safe sensors

Identification is also an issue in Ex applications.

Systems often have a mixed design, i.e. some sections are subject to explosion hazards, others are not. Available especially for surface-treatment applications (immersion baths, varnishing machines, drying etc.) as an extension of our RFID devices for Ex Zone 2 (ATEX) is the RFM 32 SL 200 Exn device with long cable (10m).

The function scope corresponds to that of the "standard device" RFM 32 SL 200 (operating range up to max. 110mm). Depending on the application, several other transponders with ATEX approval (Zone 2) are available for selection in addition to our standard selection of transponders.