E2 inductive sensors – when failure is not an option - environmental resistance

18/06/2010

The operational stability as well as the lifetime of sensors is often heavily influenced by changing environmental factors. For example changing temperatures not only influence the performance characteristics of electronic parts but are also a cause of mechanical stress due to material expansion and are also a key factor for pre-mature aging of materials. On the other hand additional protection and compensation functions may unnecessarily increase the product cost if not needed. Choosing the fitting level of environmental protection and compensation functionality is a key to selecting the optimal parts for your requirements without under- or overdesigning.

Chemical resistance

Issue

Detergents and chemicals used for cleaning or during the manufacturing process may severly damage (corode) the housings or sensing face of sensors. But apart from these conciously used chemicals, accidentally applied liquids (soft drinks with low pH values or sweat) can unintentionally damage the sensors.

Solutions

* Market standard: basic splash water protection for dry and protected machine environment.

** Tested enhanced high pressure water and saltwater spray protection with our E2A for open factory environment with occasional touching (sweat), cleaning or accidental liquid contact. The optional stainless steel housings may provide additional protection.

*** High and highest chemical resistance with our E2EH and E2FQ for frequent cleaning or intense and continuous chemical liquid contact.

Electromagnetic fields

Issue:

There are many sources for electromagnetic fields in today‘s machines, wireless communication is present everywhere in factories and the influences of electrical circuits and surrounding metal make a prediction of electromagnetic field influences nearly impossible. No or unsufficient protection in sensors may result in occasional false output signals that often go undetected but lead to quality issues in the final product.

Solutions:

* Market standard: basic protection against electromagnetic fields for uncritical machine environments.

** Tested enhanced protection against stronger electromechanical fields and wireless communication equipment with our E2A for all factory environments.

*** High resistance to strong electromagnetic fields with our E2AU for usage in mobile machines and compliance to vehicle directives.

Cable induced disturbances

Issue:

Similar to electromagnetic fields, devices in machines may cause current or voltage drops or increases in the electrical circuit that may cause false output signals. In addition accidental wrong wirings may damage unprotected sensors.

Solutions:

* Market standard: basic protection against cable induced disturbances for unchallenging electrical circuits and machine environments.

** Added protective circuits against power surges and wrong polarisation and tested enhanced protection against inverter noise with our E2A for wrong wiring and electrical circuits with potentially disturbing devices.

*** Tested additional protection against possible events in electric circuits of mobile machines with our E2AU for mobile machines.

Changing temperatures -performance

Issue:

Temperature variations in machines resulting from the operation, from usage in different regions or even from daily or seasonal fluctuations are very common. The performance and specifications of electronic components are significantly influenced by the ambient temperature resulting e.g. in variations of the sensing distance. The design of electronic circuits, the usage of compensatory elements and the balance of used parts play a vital role in reducing the sensor performance variations due to changing temperatures.

Solutions:

* Market standard: basic temperature compensation for standard factory environment.

** Designed-in enhanced temperature compensation elements with our E2A for higher operational stability in machine and factory environments even with higher temperature variations.

*** Highest temperature influence immunity by separating the sensing head from the electronic parts with our E2EC and E2C for high precision positioning applications with minimal influence by changing temperatures.

Changing temperatures - lifetime

Issue:

Rapidly changing temperatures and different expansion coefficients can lead to mechanical stress between connecting materials leading to mechanical damage or faster aging.

Solutions:

* Market standard: sensors designed for standard factory environments – faster aging or damages may occur with frequently or rapidly changing temperatures.

** Designed-in and tested enhanced lifetime with our E2A for machine and factory environments with frequently or rapidly changing temperatures.

*** Tested combinations of temperature and mechanical stress e.g. with our E2AX for special applications or certifications.

Extreme temperatures

Issue:

Continuously high or low temperatures exceeding the rated specifications quickly damage standard sensors. Suitable materials and/or product design are required for these applications.

Solutions:

* Market standard: normal ambient temperatures for operation and storage for standard factory environments.

** Specified extended operating temperature range down to -40°C with our E2A for machine operation in lower temperatures.

*** High temperature resistance up to 200°C with our E2EH and E2C for applications with high continuous temperatures.