1、 Standard Basic Information
GB/T 3836.22-2023 "Explosive Atmosphere Part 22: Protective Measures for Optical Radiation Equipment and Transmission Systems" was released
on December 28, 2023 and implemented on July 1, 2024, replacing the old version of GB/T 3836.22-2017. This standard is modified using IEC 60079
-28:2015 and is under the jurisdiction of the National Technical Committee for Standardization of Explosion proof Electrical Equipment (SAC/TC 9).
2、 Scope of application
Suitable for optical radiation equipment with a wavelength range of 380 nm to 10 μ m, including lasers, lamps LED、 Optical equipment in the form
of optical fibers, as well as optical transmission systems. Class I, II, and III equipment covering explosive gas environments (Zone 0, Zone 1, Zone 2)
and explosive dust environments, with EPL covering Ga, Gb, Gc, Da, Db, Dc, Ma, and Mb levels.
3、 Core ignition mechanism
The standard targets two types of light radiation ignition hazards:
Thermal effect ignition: The temperature of the surface or particles increases after absorbing light radiation, reaching the temperature required to
ignite the surrounding explosive environment.
Plasma ignition: The laser directly penetrates the gas at the focal point of the strong light beam, generating plasma and shock waves, which become
the ignition source; Solid materials close to the breakdown point will exacerbate this process.
4、 Three explosion-proof types
Intrinsically safe type of optical radiation (op is)
The light radiation energy generated by the equipment under normal or specified fault conditions is insufficient to ignite a specific explosive
environment mixture. Safety is achieved by limiting the power, irradiance, or energy density of the light source.
Protective optical radiation (OP PR)
Limit optical radiation within optical fibers or other transmission media to prevent radiation from escaping into explosive environments.
Optical system with interlocking device (op sh)
When the radiation limitation measures fail, the interlocking device can quickly cut off the radiation source, preventing dangerous light radiation
from entering the explosive environment.
5、 Compliance requirements for laser design
Optical radiation energy limitation
The energy of the optical radiation (continuous wave or pulse) emitted by the equipment must be lower than the minimum ignition energy of
the corresponding explosive gas, and must be verified through evaluation or beam intensity measurement.
Surface temperature control
The surface temperature of the equipment must be controlled within a safe range to avoid ignition caused by temperature rise, and must comply
with the corresponding temperature group requirements.
structural design
The equipment structure must ensure that under normal operation and fault conditions, light radiation will not cause ignition, including beam
focusing control, radiation escape protection, etc.
Not applicable exemption
Laser equipment that meets the Class 1 limit values of GB/T 7247.1-2024 "Safety of Laser Products" (for EPL Mb, Gb, Gc, Db, Dc applications) is
exempt from this standard.
6、 Typical application scenarios
After passing the GB/T 3836.22 certification, lasers can be used in places with explosive gases or dust such as petrochemicals, hazardous chemical
storage and transportation, coal mines, etc., such as laser gas detectors, fiber optic temperature measurement systems, laser radars, etc.
7、 Precautions
Environmental adaptability: Factors such as temperature, humidity, and dust concentration in the actual usage environment need to be considered,
and additional environmental adaptability testing may be required.
Maintenance requirements: The maintenance of explosion-proof equipment must follow the manufacturer's instructions to avoid damaging the
explosion-proof performance due to improper operation.
Standard update: GB/T 3836.22-2023 has replaced the 2017 version and must be implemented according to the new version after July 1, 2024.
