Explosion-Proof Technology
Technical Overview
"Our radios are designed with an explosion-proof structure to minimize the risk of ignition from electrical or thermal sources in hazardous areas containing flammable gases or combustible dust."
Our radios feature an intrinsically safe explosion-proof structure*1 and are certified by official organizations. In factories such as oil refineries, petrochemical plants, and chemical synthesis plants, flammable gas or liquid vapors may be released into the air. If these encounter an ignition source such as an electrical spark or a hot object, there is a high risk of explosion or fire. Explosion-proof electrical equipment incorporates various technical measures and approaches to prevent ignition sources from causing explosions in explosive atmospheres.
*1 Explosion-proof structure designed to prevent sparks or heat generated inside the device from igniting explosive gases.
Use cases for explosion-proof radios.
The necessity of explosion-proof design
Technical Details
To obtain explosion-proof certifications such as the ATEX (abbreviation of the French phrase "ATmosphères EXplosibles") standard*2, products must satisfy mechanical requirements and, in some cases, also address electrical requirements through mechanical approaches as described below.
*2 Explosion-proof standards established by the European Union (EU) regarding safety requirements for equipment and protective systems.
• Encapsulation structure
Explosion-proof standards require maintaining sufficient creepage distances—the surface distance between conductors—to prevent electrical current from flowing along the surface of insulators. This prevents leakage currents, discharges, and tracking caused by dust, moisture, and other contaminants. However, portable radios need to be compact, often requiring components to be placed close together, making it difficult to maintain the standard creepage distances. To address this, the radios are filled with resin internally to isolate components from the outside environment, thereby preventing explosions caused by leakage currents even when creepage distances are insufficient.
[Encapsulation structure: Before resin filling]
[Encapsulation structure: After resin filling]
• Development of a material that meets explosion-proof standards while maintaining the strength of conventional professional-grade radios.
Developing explosion-proof radios requires meeting four key material requirements simultaneously: static electricity prevention (surface resistance value below 1 GΩ), a bright blue color expression compliant with the ATEX standard, impact durability after a 65°C/1000-hour light resistance test, and passing explosion-proof tests while maintaining body strength. However, adding carbon to improve conductivity causes the material to turn black, failing the color requirement and reducing resin strength. To overcome this, we collaborated with resin manufacturers to conduct multiple prototypes and successfully developed resin material that satisfies all these requirements. This material has been used for our radios.
Bright blue resin material that meets ATEX standards
• Mechanical strength evaluation to meet explosion-proof standards
In addition to our standard internal evaluations, explosion-proof models require additional mechanical strength testing to ensure the robustness expected of professional radios.
"High Temperature/High Humidity Storage → Low Temperature Storage → Impact Test → Low Temperature Storage → Drop Test → Waterproof Test"
This entire sequence of tests must be passed with a single unit.
The testing period can last over a month, and failing the actual certification leads to delays in the development process. Therefore, we conduct thorough prior analysis and evaluation to ensure a development proceeds smoothly without any rework.
Products Incorporating This Technology
Examples of products incorporating this technology
