When specifying sensors, engineering contractors, system manufacturers and even end-users must not only ensure sensor operating specifications meet application requirements, but also validate if components address regulatory and safety requirements for the country or geographic region in which they will be installed or used.
Sensors certified domestically are not necessarily acceptable for use overseas, especially in hazardous areas such as those found in oil and gas applications, nuclear power plants, subsea as well as mining. In many countries, sensors must comply with specific national requirements to ensure safety and prevent accidents or disasters.
For example, in the European market, sensors specified for use within potentially explosive atmospheres must be certified to ATEX standards. Even if a sensor is designed for operation under hazardous conditions, units must be tested and assessed to the latest ATEX standards. See guidelines: http://ec.europa.eu/enterprise/sectors/mechanical/documents/guidance/atex
Two directives exist under ATEX certification - one for the manufacturer and one for the equipment user. In the European Union, the ATEX Directive 94/9/CE is compulsory for plants or machines, in which hazardous substances are processed or produced. It states that only ATEX-approved instruments must be used in hazardous areas within Europe. Effective April 19, 2016, this directive will be removed and replaced by a Directive 2014/34/EU. It can be downloaded at: http://www.exveritas.com/wp-content/uploads/2014/03/2014-34-EU-ATEX-directive.pdf
ATEX Directive 99/92/EC ensures workplace meets requirements for safety and health protection of workers potentially at risk from explosive atmospheres. As this directive covers the responsibilities of employers and not manufacturers, it does not pertain to sensor certification.
ATEX certification is issued only after a sensor is tested to the relevant standards applicable for each type of explosion protection applied to the equipment, such as flameproof, dust proof or intrinsically safe devices. ATEX certification is typically the responsibility of the sensor manufacturer that uses a notified body for ATEX certification.
Macro Sensors and its sister company American Sensor Technologies offer ATEX-approved LVDT Linear Position Sensors and Pressure Sensors that are manufactured and certified to operate under explosive and hazardous conditions.
When selecting a specific LVDT linear position transducer or pressure sensor, sensor users must be fully aware of the intended environment and location of its application. Look for the certification symbol, as shown above, on units or, if in doubt, ask the sensor manufacturer for clarification if the component is ATEX certified.
In addition to a UL/ULC rating (Canada) for Class I, Division 2, Groups A, B, C, and D T3C Class I, Zone 2, AEx nC IIC T3Ex nC IIC T3, Macro Sensors HLR 750 Series of LVDT Linear Position Sensors are ATEX approved in Zone 1 and Zone 2 classifications, making them appropriate for use in potentially explosive environments throughout Europe.
To reference Macro Sensors ATEX-approved LVDTs, go to: http://www.macrosensors.com/HLR_750.html
To reference, AST’s ATEX and IECex -approved Pressure Sensors, go to: http://www.astsensors.com/intrinsically_safe_pressure_transmitters.php