This product, the Flameproof and Intrinsically Safe Programmable Control Box (Model KXJ8-127), manufactured by Huaibei Hezhong Mechanical Equipment Co., Ltd., has been certified under the China Coal Mine Product Safety Mark Certification System (also known as the "MA" Mark), issued by the China National Mine Safety Mark Certification Center (formerly referred to as AQB, registered under www.aqbz.org). The certificate confirms that this control box, which combines explosion-proof (flameproof, "d") and intrinsically safe ("i") protection types, complies with the relevant Chinese national and industry safety standards, including GB/T 3836.1-2021, GB/T 3836.2-2021, and GB/T 3836.4-2021 (China's adoption series of the IEC 60079 family for explosive atmospheres), as well as MT 209-1990 (coal mine general requirements for electrical equipment) and the enterprise standard Q/HHZ009-2022.

The certificate was issued on October 20, 2022, and is valid through October 19, 2027. It also specifies that when this control box is integrated into a larger system, the relevant intrinsically safe association must be separately evaluated or tested for compliance.

The MA Mark certification is a mandatory safety approval system for equipment used in underground coal mines in China, particularly equipment installed in potentially explosive (gas/dust) atmospheres. Its scope and intent are comparable to several internationally recognized explosion-protection certification systems, including:

MSHA (Mine Safety and Health Administration, USA) approval for permissible electrical equipment used in underground coal mines

ATEX Directive (EU 2014/34/EU) for equipment and protective systems intended for use in potentially explosive atmospheres

IECEx (IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres), the global conformity assessment system based on the IEC 60079 series

Like ATEX and IECEx certifications, the MA Mark for this control box is type-specific (combining the "d" flameproof enclosure and "i" intrinsic safety protection concepts found in IEC 60079-1 and IEC 60079-11), meaning the certificate applies strictly to the certified model (KXJ8-127) and its approved technical documentation. Unlike general quality management certifications (e.g., ISO 9001), the MA Mark certification focuses specifically on explosion protection performance, electrical safety in hazardous underground environments, and ongoing post-certification supervision, with any change to registered production conditions, technical files, or key components requiring a formal variation application to the certifying body.