ATEX FAQs on industrial temperature sensors

In industrial environments with a risk of potentially explosive atmospheres, the selection of temperature sensors must comply with specific safety requirements and ATEX regulations. Misinterpretation of these requirements can lead to specification errors, project delays, or operational risks. This section explains what ATEX means in relation to temperature sensors, how it affects thermocouples and RTD probes, and which technical aspects must be correctly defined before installation.


What is ATEX and how does it affect temperature sensors?

ATEX is the European regulatory framework that governs equipment and protective systems intended for use in potentially explosive atmospheres. In the case of temperature sensors, ATEX refers not only to the sensing element but to the entire assembly installed in the classified area.

A temperature sensor for use in ATEX environments must meet requirements related to:

  • Set design
  • Components used
  • Type of protection
  • Installation conditions

For this reason, it is essential to differentiate between ATEX certified components and ATEX solutions or assemblies.


Is a thermocouple or an RTD inherently ATEX?

No. A thermocouple or RTD probe is not ATEX by definition. The ATEX status depends on the complete assembly installed in the classified area and the certified components it comprises.

In ATEX applications it is common to work with:

  • Temperature sensors designed for the process
  • ATEX certified heads, cable glands or accessories
  • Integration of the complex according to the zone and type of protection

Proper integration of the assembly is key to meeting ATEX requirements.


Difference between manufacturing a sensor and an ATEX solution

It is important to clearly distinguish between:

  • Sensor manufacturing: design and manufacture of the thermocouple or RTD according to measurement requirements (temperature, accuracy, materials).
  • Integration of an ATEX solution: selection and assembly of certified components so that the assembly can be used in a specific ATEX zone.

In ATEX applications, the correct approach is to integrate temperature sensors with certified components, respecting the installation conditions and applicable regulations.


What sensors are commonly used in ATEX zones?

In ATEX environments, the following are mainly used:

  • Industrial thermocouples, when high temperature measurements are required
  • RTD probes (PT100, PT1000, PT500), when accuracy and stability are critical

The choice between thermocouple or RTD depends on the temperature range, the required stability and the process, not on the ATEX classification itself.


Key aspects to define in an ATEX application

To correctly specify a temperature sensor in an ATEX installation, it is necessary to define:

  • ATEX zone of the facility
  • Type of atmosphere (gas or dust)
  • Operating temperature
  • Sensor type (thermocouple or RTD)
  • Required certified components
  • Mechanical and installation conditions

An incomplete definition can lead to selection errors or non-conforming solutions.


Common mistakes in ATEX applications

Some common mistakes are:

  • To think that any sensor is valid in an ATEX zone
  • Confusing a certified component with a certified assembly
  • Not considering installation and wiring
  • Oversize or undersize the equipment

A correct technical approach avoids these problems from the initial phase of the project.

Each ATEX installation has specific requirements that must be analyzed technically. If you need to specify a temperature sensor for an ATEX application, consult a qualified technician.