ATEX certification is one of the most sensitive topics when a weighing system must operate in environments where potentially explosive dusts, gases or vapours may be present. In these contexts, the choice of scales, load cells, platforms and terminals cannot depend solely on capacity, precision or data integration: it must also consider the way the system is installed, used and maintained over time.
This article does not address the classification of areas or the definition of zones, a topic that requires specific evaluation of the working environment. The focus is different: understanding how ATEX certification fits into the choice of an industrial weighing system, when it must be evaluated together with metrological compliance, and what technical questions to ask before purchasing or upgrading a system.
In many facilities, especially in the chemical, pharmaceutical, food, cosmetic and powder processing sectors, the critical point is not the individual component, but the assembly formed by instrument, environment and process.
A terminal may be installed outside the classified area, a platform may be located in a critical zone, load cells may require specific measures, and the weight data may have legal value or be purely internal. For this reason the evaluation must be technical, not purely documentary.
Why ATEX Certification Concerns the System, Not Just the Product
A common mistake is to think of ATEX certification as an isolated characteristic of the individual device. In reality, in industrial weighing the topic concerns the system as a whole: where the instrument is positioned, how it is powered, which components are inside the hazardous area, which are outside, and which connections cross the boundary between different areas.
A platform installed in a department with combustible dust present, for example, may require different evaluations compared to a terminal located in an external technical room.
Similarly, a load cell, a weighing indicator and a data transmission device may have different roles in the final configuration. The correct question is not only whether the individual component is certified, but whether the overall configuration is consistent with the environment in which it will be installed.
This approach is also important from an operational standpoint. If the terminal must be used directly by the operator in the classified area, its suitability for that context must be evaluated.
If instead the operator can work from an external workstation, it may be preferable to move the more complex electronics outside the area and leave in the field only the elements necessary for measurement. The choice depends on layout, process, weighing frequency, cleaning requirements and maintenance procedures.
ATEX, MID and NAWI: Three Concepts Not to Be Confused
In the context of industrial weighing regulations, ATEX, MID and NAWI are often cited together, but they do not indicate the same thing.
ATEX certification concerns safety in environments with potentially explosive atmospheres. It serves to evaluate whether equipment or a configuration can be used safely in a given risk context. Its objective is to prevent ignition and reduce risk to people, facilities and the production environment.
MID compliance, on the other hand, concerns legal metrology. In practical terms, it comes into play when weight is not only internal process data, but has value in commercial transactions, regulated verifications, sale by weight, labelling or dealings with third parties. In these cases it is not enough for the scale to function correctly: the system must meet requirements of reliability, verifiability and measurement control.
The term NAWI indicates non-automatic weighing instruments, that is, those in which the operator intervenes in the weighing operation, for example by positioning the load, starting the operation or confirming the result.
This distinction is essential because not all weighing systems have the same operating logic: a manual or semi-manual system poses different problems compared to a fully automated weighing system integrated in-line.
In summary, ATEX answers the question of whether the instrument can operate safely in that environment. Metrological compliance answers the question of whether that weight can be used as legally valid data. The NAWI category helps to understand what type of instrument we are dealing with and what role the operator has in the measurement.
When ATEX Is Required, When Metrological Compliance Is Required, When Both Are Required
The evaluation becomes simpler if we start from some practical scenarios.
- ATEX certification must be evaluated when the weighing system is installed in an environment where flammable dusts, gases or vapours may be present. In this case it is necessary to consider where platform, load cells, terminal, power supply and communication devices are located.
- Metrological compliance must be evaluated when the weight has commercial, fiscal, regulatory value or is otherwise relevant in dealings with third parties. This is the case for weighing operations used for sale, goods acceptance, declared dosages, transport documents or formalized controls.
- Both are required when weighing takes place in a classified environment and the weight data also has legal or contractual value. This is the most sensitive scenario, because safety and metrology must be considered together from the design stage.
This distinction avoids two opposite errors. The first is to concentrate all attention on environmental safety and neglect the legal value of the measurement. The second is to choose a metrologically suitable instrument, but not consistent with the actual installation conditions. In both cases the risk is purchasing a technically incomplete solution.
For aspects related to verification and installation of instruments, it is also useful to consult the page dedicated to installation and metric verification.
What to Verify Before Choosing the Weighing System
Choosing a compliant system starts with gathering preliminary information. Before selecting platforms, load cells or terminals, it is advisable to clarify where weighing will take place, who will use the instrument, what value the data will have, and how maintenance will be managed.
A technical manager should gather at least the following information:
- installation environment and presence of any classified areas;
- material weighed, with particular attention to dusts, vapours or flammable substances;
- mode of use: manual, semi-automatic or integrated in process;
- value of weight data: internal, commercial, fiscal or regulatory;
- need for recording, exporting and storing data;
- metrological verification, maintenance and periodic service requirements;
- layout constraints, washing, operator access and cleaning.
This information makes it possible to avoid a choice based solely on capacity and scale division. In a real system, capacity is only one of the parameters: the environment, terminal position, possibility of isolating certain components, operator readability, integration with company software and process continuity also matter.
If weighing platforms are present in the system, it is also useful to evaluate mechanical characteristics, dimensions, capacity and conditions of use. When instead the project requires evaluation of the measurement chain, load cells and connected accessories must also be considered.
The Role of Terminals in Compliant Systems
In modern weighing systems, the terminal is not just a display showing the weight. It is the point where the operator interacts with the process, where operational functions are managed, and where data useful for traceability is often collected.
This makes it a particularly important component when discussing industrial quality standards and compliance.
A terminal can support functions such as operator identification, recipe management, event recording, data export and interfacing with management systems. In a facility subject to compliance requirements, these functions help demonstrate what was weighed, when, by whom and with what outcome.
From an ATEX standpoint, however, the question always remains application-based and precedes any comparison between models: must the terminal be installed inside the classified area or can it be located outside? The entire configuration depends on this answer, not just the choice of device.
Terminals and Position Relative to the Classified Area
In the Coop Bilanciai range, the choice of weighing terminal in an ATEX project comes down to a layout decision, not a comparison of functions.
Interaction Inside the Classified Area
When the operator must use the instrument directly in the field, inside the classified area, the reference in the range is the DD700IS, the only Coop Bilanciai terminal intended for applications in potentially explosive atmospheres.
Even in this case its suitability is not limited to the device: the area classification, installation method, power supply and connections crossing the boundary between different zones must be evaluated together. A terminal suitable for the environment, but inserted in an inconsistent configuration, does not make the system compliant.
Interaction from External Workstation
When the layout allows the electronics to be located outside the classified area, leaving in the field only the elements necessary for measurement, the full range of industrial terminals opens up: OMNIA 120 for advanced interfaces and more sophisticated data management, the DD700 family in its variants for integration in panels and operator workstations, DD2060 LITE and DD2060X for more compact configurations, FLYNET 50 and the D70 series for applications where weighing and data transmission must be analyzed together.
This second configuration, when the process allows it, presents advantages worth considering already in the design phase: greater freedom in choosing the interface and data management functions, simpler maintenance, and no constraint of accessing the classified area for interventions on the terminal.
A practical criterion follows: the distance between measurement point and operator workstation is a design parameter, not a given. Evaluating it at the beginning, together with the layout, broadens the available options. Evaluating it with the system already running restricts them.
Errors to Avoid in Compliance Evaluation
The first error is considering ATEX as a requirement to tick off at the end of the project. In reality, if the environment presents critical issues, the evaluation must enter the early design phases. Moving a terminal outside the area, modifying cabling or changing the position of a platform can be simple during the layout phase, but much more costly with the system already running.
The second error is confusing safety and metrology. A system may be consistent with the installation environment, but not suitable for weighing operations with legal value. Or it may be metrologically correct, but not installable in the intended position. The two evaluations must interact, but they are not interchangeable.
The third error is taking the availability of alternatives for granted. In a classified area the range of usable components is reduced compared to an ordinary environment, and this applies to terminals, platforms and accessories. Setting up the project assuming the same freedom of choice as a non-classified department leads to revising decisions during implementation.
The fourth error is underestimating maintenance. A system compliant at the time of installation must remain manageable over time. Periodic verifications, component accessibility, availability of service and documentation are elements that affect operational continuity and the maintenance of compliance.
The fifth error is not involving operators. A terminal installed correctly but difficult to use can generate errors, cancelled weighing operations, incomplete records or procedures not followed. In non-automatic weighing instruments, where the operator intervenes in the weighing operation, usability is part of process quality.
How to Set Up a Preliminary Technical Verification
An effective preliminary verification should start from three questions: where does weighing take place, what value does the weight have, and what environmental conditions affect the system. From these answers derive the choices on platform, cells, terminal, cabling, accessories, software and verification services.
Discussion with the supplier should include system layout, position of critical areas, distance between measurement point and operator workstation, weighing frequency, cleaning procedures and data recording requirements. Only after this analysis does it make sense to discuss model, configuration and options.
For further information on available devices, the page dedicated to weighing terminals can be consulted. If instead the project requires a broader evaluation of installation, metric verification and system compliance, it is possible to contact Coop Bilanciai.
FAQs
What Does ATEX Certification Mean in Industrial Weighing?
It means evaluating whether a weighing system or component can be used safely in environments where explosive atmospheres may form. The evaluation must consider not only the product, but also installation, connections and operational context.
Which Coop Bilanciai Terminal Is Suitable for Classified Areas?
The DD700IS is the terminal in the range intended for applications in potentially explosive atmospheres. The other models must be located outside the classified area, leaving in the field only the components necessary for measurement.
What Is the Difference Between ATEX and Metrological Compliance?
ATEX concerns safety in potentially explosive environments. Metrological compliance concerns the validity of the measurement when weight has commercial, fiscal or regulatory value. In some systems both evaluations are required.
What Are NAWI Instruments?
NAWI instruments are non-automatic weighing instruments, that is, systems in which the operator intervenes in the weighing operation. This may include positioning the load, starting the operation or confirming the result.
When Is It Necessary to Also Evaluate Metrological Compliance?
It must be evaluated when weight has legal or commercial value, for example in sale by weight, goods acceptance, labelling or official documents. It does not concern all internal process weighing operations.
Is Choosing a Certified Component Enough to Have a Compliant System?
No. Compliance depends on the overall configuration: environment, installation, cabling, accessories, operational use and maintenance. The individual component is important, but does not replace evaluation of the system.