Hazardous Locations – Unit Verification

The main difference between Unit Verification and Certification is that with unit verification, the Certification/Inspection Body representative must affix the labels on the equipment, whereas with certification, manufacturers are authorized to apply the labels themselves. Some of the benefits of Unit Verification…

The benefits of Unit Verification are:

• manufacturers don’t have to maintain a production line or quality resources;
• it allows for approval of one or a batch of units;
• it’s faster and more practical than certification;
• manufacturers don’t have to absorb the cost of recurring listing fees as overhead.

Certification, or Listing, is the process of allowing manufacturers to affix the labels on the product themselves, once the product is certified. After the certification is completed, and to maintain the certification, the Certification Body must conduct factory assessments at the manufacturing facility to validate that the products being labelled are the same products that were originally certified. Depending on the product category, the frequency for factory inspections is usually once every quarter, for North American approvals, and every 12-18 months in the case of IECEx/ATEX . Products can be tested either onsite or at the third party lab. Once the product meets the minimum construction evaluation and testing requirements, as per the standard, as well as the manufacturer’s quality system has passed Initial Factory Inspection (North America) and QAR/QAN (IECEx/ATEX) then the certificate is issued to authorize the manufacturer to be able to label the products before shipping themselves. The manufacturer performs any factory tests if applicable as per standard requirements. The benefit of this model is for mass manufacturing and to reduce lead time to be able to ship the units.