Shenzhen ZhongNuo Testing Technology Co., Ltd. is based in South China and specializes in explosion-proof certification and coal safety certification application consulting services, offering a one-stop explosion-proof technology consulting service.
Explosion-proof Certificate Application Documents and Process Requirements | ZN Testing
The explosion-proof certificate is a type of explosion-proof certification model for products outside the explosion-proof 3C catalog.
As of October 1, 2009, a portion of explosion-proof electrical equipment was included in the CCC certification catalog, which is a mandatory product certification. Products listed in the catalog require an explosion-proof 3C certification, following the "product testing + factory audit" model. For a detailed explosion-proof 3C certification catalog, please refer to the relevant information on our website. Explosion-proof products not listed in the catalog can opt for a certificate of conformity, which can be obtained simply by passing the product testing.
The general process for obtaining an explosion-proof certification includes: submitting product-related documents, conducting product testing, and upon passing the test, issuing an explosion-proof certification. During the application process, ensure your product meets the relevant explosion-proof standards and requirements.
If you're unfamiliar with explosion-proof standards and certification requirements, no worries. Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof design and modification services, as well as certification agency services for intrinsic safety, flameproof, encapsulation, and positive pressure types, to help businesses conveniently obtain explosion-proof certificates.

【Ex-proof Certification Mark】How to Read the II Class Ex-proof Mark?
What does the II class explosion-proof marking actually include? Let's break it down, once you understand it, you'll never be conned again!
Firstly, Category II signifies non-mining gas explosion-proof, which is the fundamental premise. "Ex" stands for explosion-proof, followed by the explosion-proof type, such as Exd (flameproof) and Exe (intrinsic safety), but the specific markings must be consulted. Then comes the gas group and temperature group, EPL is the equipment protection level, all of which are key parameters in determining the explosion-proof performance.
Not all II-class explosion-proof devices are the same. For instance, some explosion-proof certificates mark it as "IIB+H2" without a temperature group. This situation requires attention. Additionally, the explosion-proof types of associated equipment, such as intrinsically safe barriers with brackets, as well as non-electric explosion-proof devices, all fall under the category of II-class explosion-proof.
For more information on explosion-proof markings, please feel free to contact Shenzhen ZhongNuo Testing Technology Co., Ltd. at any time!

Shenzhen Zhongnuo Inspection introduces you to the basic process of explosion-proof certification
Explosion-proofing primarily involves the following key steps, with the entire process typically taking around 2 months.
1. Specify certification requirements
Determine the certification type based on the product's intended use and target market, such as domestic explosion-proof certificates, explosion-proof 3C certification, or international certifications (e.g., ATEX certification, IECEx certification).
2. Prepare inspection documents
Three types of documents must be prepared:
Product Technical Documents: Assembly Diagrams, Electrical Schematics, Electrical Parts List, Product Manual, Corporate Standards, etc.
Corporate Qualification Documents: Business License
‌Inspection Sample Instructions: Samples must match the technical documents and include a certification of compliance for explosion-proof accessories (if applicable).‌
3. Drawing and Documentation Review
Shenzhen ZhongNuo's explosion-proof engineer will thoroughly assess the conformity of the provided product drawings and certification requirements against explosion-proof standards. They will promptly propose rectification suggestions and requirements, and the client is expected to cooperate in the necessary improvements.
4. Sample Inspection
Samples are sent to the lab for explosion-proof testing, which includes explosion-proof structure inspection, temperature class testing, IP protection level tests, etc. The testing cycle typically ranges from 2 to 4 weeks.
5. Factory Inspection (if applicable)
Factory audits for explosion-proof 3C certifications are required, including inspections of production equipment, process flows, and quality system documents.
6. Audit and Certification
Upon passing the inspection, the certification body reviews the documents and issues a防爆 certification or防爆3C certificate.
The above information is shared by Shenzhen ZhongNuo Testing Technology Co., Ltd. For detailed requirements on explosion-proof certification, feel free to contact us!

ZheNuo Inspection | What do the explosion-proof markings on explosion-proof electrical equipment signify?
The explosion-proof marking on explosion-proof electrical equipment indicates the specific explosion-proof characteristics and applicable environments of the equipment. These markings are typically composed of a series of letters and symbols, each part having a specific meaning.
Firstly, the Ex marking indicates electrical equipment for use in explosive gas atmospheres, signifying that the device is specifically designed for explosion-proof environments.
Next, there is the marking for the protective type, such as ib, db, eb, etc. These letters indicate the type of explosion-proof protection used by the equipment, for example:
The "ib" indicates intrinsic safety protection, meaning that the equipment cannot ignite an explosive gas mixture under normal operation or under specified fault conditions, as it does not produce electric sparks or thermal effects.
db indicates explosion-proof protection, meaning that in the event of an explosion inside the equipment, flames and explosion products propagate to the outside through the equipment's junction surfaces or structural gaps.
EB indicates an explosion-proof protection, which means improving the structure and materials of the equipment to enhance its safety performance.
Then comes the marking for the gas environment, such as I, IIC, etc. These letters indicate the category of explosive gas environment for which the equipment is suitable, for example:
I signifies the coal mine gas environment.
IIC indicates that the equipment is suitable for IIC category gas and vapor environments, which typically include more dangerous explosive gases, such as hydrogen sulfide and methane.
Next is the identification of temperature categories, such as T6, T4, etc. These numbers indicate the limit of high surface temperature of the equipment, for example:
T6 indicates that the equipment's surface temperature does not exceed 85°C.
T4 indicates that the equipment's surface temperature does not exceed 135°C.
Next is the equipment protection level indicator, such as Mb, Gb, etc. These letters represent the protection area level applicable to the equipment, for example:
Mb indicates that the equipment is suitable for the 1st area of coal mine gas environment.
Gb indicates the equipment is suitable for Zones 1/2.
In summary, the explosion-proof marking of explosion-proof electrical equipment is a significant indicator of the device's safety performance. Users should carefully inspect and understand the meanings of these markings when using and selecting equipment. For more information on explosion-proof certification and markings, please feel free to consult Shenzhen Zhongnuo Testing Technology Co., Ltd., where we will provide you with further clarification.
Explosion Proof Certification Application Consultation Service - Shenzhen Zhongnuo Testing Technology Co., Ltd.