I often find myself explaining to customers what goes into the IECEx certificate that they're looking at. Usually this is to explain a difference between Australian requirements and European requirements (ATEX), or to explain why it is important that the certificate number be marked on the equipment to prove that the certificate applies.
It is helpful for me to understand this by asking what the certificate is supposed to prove. There are two elements to this.
- That the equipment is designed according to a standard.
- That the equipment is manufactured according to the design.
Does the design of the equipment satisfy the standard?
This is the easy part which most readers will understand. We know that to get a certificate, the equipment is subjected to tests (and other assessment) by the certification body.
Under the IECEx system however, the certification body does not issue a certificate after conducting these tests, the document they issue is a test report (ExTR).
The ATEX directive is different. The EU Type Examination Certificate (what you would commonly call an ATEX certificate) only tells us that the representative sample or 'type' has been tested and found to comply. The ATEX certificate fills the same role as the ExTR does in the IECEx system.
Does the equipment supplied to me satisfy the design?
This is where it gets a bit tricky, as there are a couple of ways the manufacturer can achieve this.
-
Implement a quality management system to ensure that the equipment manufactured is (effectively) the same as the sample which was tested.
-
Have the certification body test each product, or each batch.
Under the IECEx system, option 1 requires an audit by the certification body who then issues a Quality Assessment Report (QAR). Option 2 would result in a Unit Verification Certificate, which only applies to a specific serial number or range of serial numbers.
Under the ATEX directive, option 1 can mean the manufacturer checks themselves (internal production control) or they could have a notified body audit their quality system and issue a Quality Assurance Notification or a similar document. The notified body audit is required for electrical equipment for Zones 0/1/20/21. There are also other options which don't have a direct comparable in the IECEx system, such as 'product verification' and 'supervised product testing'.
For ATEX, option 2 would result in the notified body issuing a 'certificate of conformity' which should state that it is for unit verification and the serial numbers that it applies to.
How do I know both have been fulfilled?
For IECEx, once the certification body has both an ExTR and a QAR, they can issue a certificate of compliance. The 3 documents can even be issued by 3 different bodies!
For ATEX, the notified body who does the testing doesn't need to know anything about the manufacturer's quality system, they can just issue a certificate. The manufacturer is the one with a legal obligation to ensure they have both aspects covered, and they tell you about that by issuing a Declaration of Conformity.
Often this topic comes up because an installer shows me a certificate which covers model ABC from manufacturer XYZ, but that certificate number isn't marked on the model ABC in front of us.
Since the certificate number isn't marked, we don't know whether it applies to this specific model ABC. Maybe it was marked incorrectly, or maybe it was manufactured in a different location (or even on a different line at the same manufacturing location) which doesn't have the audited quality system in place. The point being that without the marking on the equipment, we can't be confident that this model ABC complies.
The only way to confidently trace the equipment's certification is for the equipment to be marked with the certificate number.
Comparison table
| IECEx document | ATEX document | |
|---|---|---|
| A representative sample has been tested: | ExTR | EU Type Examination Cert |
| The quality system has been audited: | QAR | QAN |
| Required document for the end user: | Certificate of Conformity | Declaration of Conformity |
As you can see from this table, ATEX only ever requires self-verification of the entire picture. This is why Australia does not directly accept an EU Declaration of Conformity (or an EU Type Examination Certificate) as evidence of compliance for Ex Equipment.