The possibility of residual dust build up, leading to a low-level risk of explosion is quite prevalent in many industries. Areas where this risk is identified should be classified as a Zone 22, requiring ATEX Equipment Category 3D for any control products in use where the risk is present. To comply with the requirements for 3D, sensors and other products must now comply with a standard such as IEC60079-31. While other protection concepts are available, for Zone 22 equipment, rugged, dust-tight enclosure is the most appropriate for sensors.
ifm's new range of ATEX 3D inductive and capacitive sensors is fully compliant. This is no mean feat, as the requirements for IEC60079-31 are much enhanced in comparison with earlier standards.
In order for the manufacturer to certify products to IEC60079-31, sensors must be tested to withstand a 4 Joule impact (10 times the previous requirement) even if the operator takes precautionary measures when fitting them. This is made harder by the fact that plastics must be conditioned, i.e. artificially aged, before the impact test. After the impact test, sensors must maintain their design IP rating.
ifm electronic now offers inductive sensors in M12, M18 and M30 threaded housings, and common rectangular sizes, plus capacitive in M30 and rectangular. Versions exist for DC or AC operation.
Some of the most rugged sensors on the market are the result, with other uses beyond ATEX Zone 22. It is believed that not many sensor manufacturers offer such a range of inductive and capacitive proximity sensors that complies with the current standards.
For further information about ifm’s range of ATEX 3D inductive and capacitive sensors please visit www.ifm-electronic.co.uk.