工业施工场所常常会对人体造成伤害，为此，人们发明了一些防护工具。其中，焊接面罩是一种能够保护焊接工作人员安全的工具。它通过集成光学、电子学、人体学、材料学等学科的技术，采用优质的LCD与镀玻璃组合为遮光镜片。
这种遮光镜片上的光感应系统能在瞬间探测到电焊时弧光的产生与消失，迅速驱动液晶体遮光变色从而保护焊工的眼、面部避免弧光辐射的伤害。它不仅能够双重滤光，避免电弧产生的紫外线和红外线对眼睛造成的伤害，还能够有效防止作业出现的飞溅物和有害体对脸部造成侵害，降低皮肤灼伤症的发生。
此外，焊接面罩能够通过气流导向，有效减少焊接释放的有害气体和灰尘等对体内造成伤害，预防尘肺职业病的发生。采用高分子材料一次成型，高强度，不漏光，更适合当前潮流，而齐全的品种能够适应多种工作环境需求。
相比传统的电焊面罩，光控焊接面罩具有更好的防护效果，它可以清楚地看见焊接工件，在起弧瞬间自动变暗。光控焊接面罩是一种应用了光探测技术与液晶技术的新型焊接面罩。内部的光电传感电路在检测到焊接时产生的光线（主要是红外线或是紫外线），经过放大，触发液晶的控制电路，并根据预设的光透过率在面罩的液晶（透射式TN液晶）施加相应的驱动信号。液晶作为光阀将改变其透光度，滤去焊接产生对人眼有害的红外以及紫外线。同时，将强光减弱到人眼可以承受的弱光。这种面罩不仅可以保护操作人员的健康，还可以清晰地观察焊接的全过程，是传统焊接面罩的理想替代品。
变暗范围可以在9#~13#间调节。除了光控焊接面罩，宽视野碳素面罩也是一种结合光控焊接面罩优点的新型焊接面罩。它除了拥有出色的基本防护性能外，还可以搭载焊接送风系统，提供更高的呼吸防护，适用于在复杂环境下作业。
焊接面罩的质量应符合GB3609．1-94的规定，其中面罩尺寸应符合有关规定。头带式面罩（不含滤光片和保护片）的重量应该在560g以下，手持式的重量应该在500g以下。同时，面罩材料厚度应该为1.5mm(0.2mm)，观察窗、滤光片、保护片和尺寸要吻合，要有很好的固定装置，不能从缝隙中漏入辐射光。铆钉及其他部件要牢固，没有松动和脱落现象，而且金属部件不得与人体面部接触。前挂眼镜上、下掀动要方便。面罩材料必须用不导电的材料制作，耐燃性能经试验，燃烧速度应小于760mm/min。金属部件经10%食盐溶液浸泡15分钟后取出，不擦去表面液体在室温下干燥24小时，然后用温水洗涤，观察表面应无变化为合格。
When it comes to welding work, one of the most important pieces of equipment is the welding helmet or welding shield. This protective gear is used to shield the eyes and face from the intense light and heat generated during welding. But what exactly is the purpose of a welding helmet and what are the standards that govern its use?
First and foremost, a welding helmet is designed to protect the welder's face and eyes from the intense light and heat produced during welding. It also provides protection from any sparks or debris that may be thrown off during the welding process. In addition to these primary functions, a welding helmet should also be comfortable to wear for extended periods of time, and should not obstruct the welder's vision or movement in any way.
There are various standards that govern the use of welding helmets, such as ANSI Z87.1-2015, which outlines the minimum requirements for eye and face protection for welders. It stipulates that welding helmets should meet certain standards for optical performance, impact resistance, and coverage area. Specifically, welding lenses must have a shade number that corresponds to the type of welding being performed. For example, the recommended shade number for shielded metal arc welding (SMAW) is 9, while the recommended shade number for gas tungsten arc welding (GTAW) is 11.
Another important factor to consider when selecting a welding helmet is the size and fit. Welding helmets come in various sizes and shapes to accommodate different head sizes and shapes. It's important to choose a helmet that fits snugly, but not too tightly, and that can be adjusted for a comfortable fit.
When it comes to the materials used in welding helmets, polycarbonate is a common choice for the lens material due to its high impact resistance and optical clarity. The lens should also be coated with an anti-fog and scratch-resistant coating to ensure clear vision and durability.
In addition to the welding helmet itself, there are also accessories and features that can enhance its performance and comfort. For example, some welding helmets come equipped with a respirator to filter out harmful fumes and particles, while others may have a respirator attachment that can be purchased separately. Some helmets also feature a flip-up design for easier access to the weld site, or a pivoting headgear for a more customized fit.
Overall, the welding helmet is an essential piece of protective gear for welders that should meet certain standards for optical performance, impact resistance, and coverage area. When selecting a welding helmet, it's important to consider factors such as the size and fit, lens material and coating, and any additional features or accessories that may enhance its performance and comfort.
