What is UL certification?（2）

The types of UL's product certification and testing services can be divided into listing, accreditation and classification.

1. LISTED:

In general, listing only applies to complete products and various components and devices that are replaced or installed in the field by qualified personnel. The various products that fall under the UL listing service include: household appliances, medical equipment, computers, business equipment And various electrical products that function in buildings, such as power distribution systems, fuses, wires, switches and other electrical components. Products listed by UL can usually be marked with the UL listing mark on each product. Usage of column name flags.

2. Recognized:

The accreditation service is a project in the UL service, and the identified products can only be used as components and raw materials on UL listed, graded or other recognized products. Approved products are not structurally complete, or have certain limitations in use to ensure the expected safety performance. Tracking services for approved products fall under category R in most cases. Approved products belonging to category L are electronic wire (AVLV2), processing wire (ZKLU2), wire harness (ZPFW2), aluminum wire (DVVR2), and metal flexible tube (DXUZ2). Approved products are required to carry the approval mark.

3. Classification:

The grading service only evaluates the specific hazards of the product, or evaluates the products that implement standards other than UL standards (including internationally recognized standards such as IEC and ISO standards, etc.). In general, most graded products are not intended for consumer use, but are intended for industrial or commercial use. The grading mark in the UL mark indicates that the product has certain restrictions and regulations when it is identified by UL. For example, chemicals such as industrial solvents are evaluated only in the range where fire may occur when the temperature reaches the ignition temperature. The grading service and listing service of some products are the same, but generally only one or several aspects of the product are evaluated. For example, in the United States, equipment such as medical X-ray diagnostic equipment must abide by US laws and related radiation emissions and beams nationwide. However, because UL only regards X-ray as a graded product, it only evaluates its mechanical properties, electrical properties and other non-radiative properties.