This relates to capacitive sensors. The effective operating distance is the operating switching point at nominal voltage and at nominal temperature of 23°C. It is between 90 % and 110 % of the rated operating distance.
The EMC class is a measure of the noise immunity of the sensor against external electrical and magnetic influences. The information is based on the standard EN 61000-6-2.
On for example a chemical plant there may be present certain products that will ignite under certain conditions. As electrical apparatus can generate a spark and cause explosions steps have to be taken to prevent this. If something is explosion proof then it is contained within an enclosure which will withstand an internal explosion of a flammable gas or vapour that may enter it, without suffering damage and without communicating the internal flammation to the external explosive atmosphere, through any joints or structural openings in the enclosure. The enclosure will be designed for a particular gas grouping (I, IIA, IIB or IIC). This design concept is reflected in the equipment marking by the symbol ‘Ex d’. Equipment designed to this concept is suitable for use in ‘Zone 1’ and ‘Zone 2’ classified hazardous areas.
Powelectrics have developed an ATEX approved GSM / GPRS Telemetry device – the METRON ATEX.