The laser cutter laser is a special type of power source. It emits radiation to a certain extent, and how harmful is this radiation?
Depending on the laser irradiation, the CDRH and IEC divide the damage of the laser and laser products into four grades, based on the AEL processable radiation limit (which refers to the maximum allowable laser radiation at each level and for products at laser).
AEL is related to the wavelength and time of exposure to radiation.
1st Level:
Under normal operating conditions, there is no radiation harmful to humans.
2nd Level:
The range of its radiation is in the visible spectrum region, and its AEL value is equivalent to the value of 0.25 seconds of exposure to radiation from the first stage product.
The product requires additional warning marks for safety testing.
3rd Level:
It is divided into levels 3a and 3b.
For people who have a normal avoidance response to strong light, level 3a will not cause harm to the naked eye, but in the case of observation through the use of lens instruments, it will cause harm to people's eyes.
Level 3b includes radiation from 200 nm to 1,000,000 nm, which can cause accidental damage when seen with the naked eye.
Management and control at this level are more rigorous than the second level.
4th Level:
Above the third level, it not only hurts human eyes when looked at directly, but can also cause injury in other situations, such as skin, or even cause fire.
Strict management and control of this type of product must be carried out.
According to the CDRH standard, the output power of the first-tier product must be less than 8.5 mW for the laser device and the single-mode optical fiber communication system that uses a 1550 nm laser.
If the power is greater than 500mW, then it belongs to the 4th level.
According to the IEC standard, the output power of the first stage product must be less than 10mW for the laser device and single-mode optical fiber communication system using a 1550nm laser.
If the power is less than 50mW, it belongs to the 3rd level. If it is greater than 500mW, it is the 4th level.
After the introduction of optical fiber amplifiers into an optical communication system, radiological safety has received much attention because the output power of optical fiber amplifier is higher than that of general semiconductor lasers.
When the International Telecommunication Union (ITU-T) creates standards for the optical communication system, especially for the use of fiber optic amplifier systems (such as WDM), they take into account the safe use of lasers.
In some recommendations such as G. 691, G. 692, G. 664, G. 957, etc., definitions and descriptions related to IEC 825 are introduced.
The light from a laser cutting machine is different from other common lights.
The laser generated by the laser source is monochromatic, coherent, collimated and has high energy density.
Therefore, it can achieve the effect of energy concentration and cause damage to human organs (especially eyes).
For lasers in the infrared spectrum region, the damage to the human body is mainly due to thermal effect, while lasers in the blue and ultraviolet spectrum region mainly cause photochemical damage.
Therefore, when the human eye is directly exposed to a laser from a laser source or fiber optic connector, it can cause damage to the eye.
If it is an ultraviolet laser, it can cause corneal inflammation and cataracts.
For current laser sources that use a 1550nm laser, the light source of the laser marking machine is in the far-infrared range, which mainly causes damage to the cornea and lens of the eye.
