Lanyu laser takes you to understand the safety level of laser standards

With the rapid development and wide application of laser technology, a variety of laser products can be seen everywhere in our life and work environment. Some laser products can be used safely, but some improper use will cause serious damage to our eyes and skin, and even cause fire, electric shock, scald and other serious accompanying hazards. So how can you know whether a laser product is safe?

Overview of laser grade safety

In order to allow users to easily identify the danger level of laser products, we can classify laser products according to the mechanism of harm to human tissues and the degree of damage caused by laser products.

The wavelength and power of laser products determine the damage of laser to different tissues of human body. Wavelength determines the absorption characteristics and harm mechanism of different human tissues, while power and energy determine the harm degree of laser. The International Electrotechnical Commission standard divides laser products into several safety levels according to the wavelength, maximum output laser power or energy of laser products. They are like the name card of laser products, representing the harm degree of laser products, and the matters that users need to pay attention to.

Laser safety grade classification details:

According to the International Electrotechnical Commission standard (IEC 60825-1), laser products are classified into the following seven grades: 1, 1M, 2, 2M, 3R, 3B and 4, based on the wavelength and maximum laser power output. Among them, the two levels of 1M and 2M represent that the safety level of the product is the same as that of Level 1 and Level 2 respectively. However, when using optical equipment such as telescopes, the harm degree may be amplified to exceed the harm of Level 1 and level 2. Level 3 is also divided into two sub-levels, 3R and 3B.

The specific classification of laser and the harm degree represented by different categories:

Laser class classification and its representative harm degree

Class I: Low output laser (power less than 0.4mW) does not exceed the MPE value for eyes and skin under any conditions, even after focusing through optical systems. Can ensure the safety of the design, without special management. Typical applications include laser pointer, CD player, CD-ROM equipment, geological exploration equipment and laboratory analytical instruments, short distance communication transmission, etc. (Use when light source is exposed)

Class II: Low output visual laser (0.4mW-1mW), the reaction time of human eyes closing is 0.25 seconds, using this time to calculate the exposure can not exceed the MPE value. Usually less than 1mW laser, will lead to dizziness can not think, with closed eyes to protect, can not say completely safe, do not directly in the beam of observation, do not use the Class II laser directly irradiate other people's eyes, avoid using far-sight equipment to observe Class II laser. Typical applications include classroom demonstrations, laser Pointers, sighting equipment and rangefinders.

Class III: Medium output laser beam, if directly into the eye can cause injury, for certain safety reasons, further classified into Class IIIA and IIIB.

Class IIIA is visible light continuous laser with output of 1-5mW laser beam. The energy density of the beam should not exceed 25W/m-m. Observation of IIIA laser with far-sighting equipment should be avoided, which may increase the danger. Typical applications of IIIA and Class II have many similarities, such as laser pointer, laser scanner, etc.

III Class B continuous lasers of 5-500mW, dangerous to observe directly within the beam. However, the minimum irradiation distance is 13cm and the maximum irradiation time is less than 10 seconds. Typical applications of IIIB laser are spectroscopic determination and entertainment light shows.

ClassIV: high output continuous laser (greater than 500 mw), higher than the third level, there is a risk of fire, diffuse reflection is dangerous. Typical applications include surgery, research, cutting, welding and micromachining. Level 1 is used in such as a laser pointer, CD players and cd-rom device, geological prospecting equipment and laboratory analysis instruments, etc. (Used when the light source is exposed) because the power is less than 0.4mW. So it's not harmful to the eyes. But also because he takes the distance is not more than 1 meter, so it can not be applied in optical fiber temperature measurement, for some manufacturers put forward 1 grade, impossible to do. In other words, he's got another laser in his mainframe level one, but it's definitely not a temperature source.

In the process of R&D and commissioning, we sometimes cannot determine the laser grade of a certain part of the product. At this time, we cannot simply assume that the grade is the same or lower than the laser source grade because of the trouble. On the contrary, we generally assume that it is Class 3B or even Class 4 grade and take adequate safety precautions. For example, wear laser protective glasses, protective gloves, etc., to avoid accidents.