ATEX Level Sensors for Hazardous Areas

ATEX Level Measurement: Safe Sensor Solutions for Hazardous Areas

In many industrial applications, potentially explosive atmospheres can arise, for example due to flammable gases, vapours or dusts. In such environments, special requirements apply to sensor technology and measurement systems. In particular, for level measurement in hazardous areas, the design, materials and electrical configuration must be carefully matched to the specific application.

Reed develops sensor solutions specifically designed for use under demanding conditions. These include products in Ex design for reliable level measurement in explosion-protected applications. These solutions are used wherever liquids are produced, stored or transported and where explosive atmospheres may occur.

Typical applications range from tank systems in the chemical industry to uses in the oil and gas industry or hydrogen technology. Sensors in Ex design can also be used in specialised environments with particularly high requirements for safety and reliability.

Reed offers various sensor principles for level measurement in hazardous areas. These include both point level sensors and solutions for continuous measurement. The designs are adapted to the respective requirements, for example in terms of medium, installation situation or temperature range.

What Characterises Products in Ex Design

Products used in hazardous areas must meet specific safety requirements. Even small sparks, high surface temperatures or electrostatic discharges can, under certain conditions, ignite an explosive atmosphere. Therefore, sensors for level measurement in hazardous applications are specially designed and tested.

For use in such environments, it is essential that electrical and mechanical components are designed in such a way that no potential ignition sources are created. This includes, for example, the design of electrical contacts, the selection of suitable materials and the limitation of energy and temperature within the system. Depending on the application, different types of protection may be used, such as intrinsically safe circuits or specially encapsulated designs.

Classification into the appropriate zones also plays an important role in the selection process. In practice, hazardous areas are classified depending on the frequency and duration of the occurrence of an explosive atmosphere. The design of the sensors must match the respective zone and reliably take the intended operating conditions into account.

Our Ex Standard Explained Briefly

For our intrinsically safe versions of float switches and level transmitters, the marking Ex ia IIC T6…T4 Ga as well as Ex ib IIIC Ta Db applies. This enables us to offer sensor solutions for applications in gas and dust hazardous areas, provided the design matches the specific installation situation.

The marking can be interpreted as follows:

• Ex stands for use in hazardous areas.
• ia / ib indicates the type of protection, intrinsic safety. ia in our sensors covers applications up to Zone 0 in gas environments. ib in our design refers to dust environments up to Zone 21.
• IIC / IIIC designates the gas or dust group. IIC also includes highly flammable gases such as hydrogen. IIIC refers to dusts with the highest requirements.
• T6…T4 describes the temperature class. It indicates the maximum permissible surface temperature during operation. The applicable class depends on the specific application and operating conditions.
• Ga / Db describes the equipment protection level. Ga stands for use up to Zone 0, Db for use up to Zone 21.

More information can be found in our ATEX documentation / test reports.

We supply the sensors in the appropriate Ex design together with the corresponding type examination certificate for this Ex standard. The assessment of the overall system, for example zone classification, selection of additional Ex components or installation within the complete system, is not part of our scope of services. For this, we recommend consulting a specialised Ex planner.

It is also important to note: In this area, we offer intrinsically safe solutions according to Ex i. Other types of protection are not included.

Reed Products in Ex Design for Various Applications

We offer various sensor solutions in Ex design for different applications of level monitoring. Depending on the requirements, point level sensors or systems for continuous level measurement are used in hazardous areas. The selection depends on the medium, tank geometry, installation situation and the respective process conditions.

Float Switches for Point Levels and Switching Points

Float switches are used to reliably monitor defined fill levels. Typical functions include overfill detection, empty detection or pump control. For applications with explosive atmospheres, these sensors can be implemented in Ex design.

Depending on the application, different designs are possible, such as vertical or horizontal mounting variants. Multiple switching points within a single sensor can also be realised. This allows, for example, simultaneous monitoring of minimum and maximum levels. These solutions are particularly suitable for tanks, containers or storage systems with flammable media.

Thanks to their robust design and application-specific configuration, float switches can also be used under demanding conditions. These include applications with changing temperatures, different media or limited installation space.

Transmitters for Continuous Level Measurement

In addition to point level solutions, Reed also offers transmitters for continuous level measurement in explosion-protected applications. These sensors measure the level across the entire measuring range and transmit a corresponding output signal to the control system.

Depending on the design, different signal types are available, such as analogue output signals or resistance values. This allows the sensors to be flexibly integrated into existing systems. Continuous level measurement in hazardous areas is particularly useful when processes need to be precisely monitored or controlled.

These sensors are also adapted to the specific application. Different lengths, materials or mounting options are possible. This enables both small containers and larger tanks to be equipped with reliable level measurement in hazardous areas.

Typical Applications for Reed Sensor Technology in Hazardous Areas

Sensor solutions in Ex design are used in many industries where explosive atmospheres may occur. This particularly includes applications with flammable liquids, gases or vapours. Level measurement in hazardous areas is used, among other things, for process monitoring, overfill protection or system control.

Typical application areas include:

1. Oil and Gas Industry
   Monitoring of tanks, storage facilities and process vessels with flammable media as well as control of transfer and conveying systems.
2. Chemical Industry
   Level monitoring in systems with solvents, chemicals or other flammable substances.
3. Pharmaceutical Industry
   Applications with alcohol-based or highly flammable media in production and storage containers.
4. Tank Farms and Storage Tanks
   Overfill protection and continuous level measurement in hazardous storage areas.
5. Hydrogen Production and Hydrogen Storage
   Monitoring of tanks and process systems in applications with hydrogen-based media.
6. Process Plants and Industrial Containers
   Level measurement in hazardous areas within production systems with potentially explosive atmospheres.

Selection and Custom Design of Ex Sensors

• Medium
  Properties such as density, viscosity or chemical resistance influence the selection of materials and sensor type.
• Tank or Container Geometry
  Shape, size and installation situation determine the appropriate sensor length and design.
• Temperature and Pressure Conditions
  Operating conditions affect the choice of materials and the technical design.
• Installation Situation
  Vertical or horizontal mounting as well as limited space conditions influence the design of the sensor solution.
• Signal Processing and Interfaces
  Depending on the application, different output signals or switching functions are required.
• Requirements for the Ex Design
  The classification of the environment and the intended operating conditions determine the necessary sensor design.

Years of experience in the development of sensor technology for hazardous applications enable us to implement even demanding projects. From the initial technical coordination to the final solution, we support projects in a practical and application-oriented manner. Reliability, safe operation and a design tailored to the specific application are always at the core of our approach.

FAQs – Frequently Asked Questions About Products in Ex Design

When is Level Measurement in Ex Design Required?

Level measurement in Ex design is required when an explosive atmosphere may form in the surroundings or inside a tank or container. This is the case, for example, with flammable liquids, gases or vapours.

Which Sensors are Suitable for Hazardous Areas?

Depending on the application, point level sensors such as float switches or transmitters for continuous level measurement are used in hazardous areas. The selection depends on the medium, installation situation and process requirements.

Which Industries Use Level Measurement in Hazardous Areas?

Typical industries include the oil and gas industry, chemical industry, pharmaceutical industry, tank storage, hydrogen applications as well as various industrial process plants.

Can Multiple Point Levels Be Monitored Simultaneously?

Which Factors are Important When Selecting an Ex Sensor Solution?

Key criteria include the medium, temperature, pressure, tank geometry, installation situation as well as the requirements for the explosion-protected design.