Auto Darkening Lens Reaction Time

[biggerten]

........... (1/25,000 sec, or 0.4mS), but I was still leery of the Chinese helmets..................

.....................at 1/2750 sec., or almost 4mS! ................

JayC

Check yer math, yer gonkulator is misplacing the decimal point.

 

[yomax4]

I used to sell several brands of AD Helmets. The switching speed is more to protect you from initial arc flash than UV/IR. Most brands protect you to the equivellent of shde 16 even in the light state. Although you won't want to weld in the light state, You could and still be safe. You may get eye irritation but you won't suffer UV/IR damage. The better hoods have a delay feature that keeps the shade dark until the puddle cools below white hot. Although Plasma calls for shade 8 or darker, You can cut safely on grind mode which is shade 3-5 depending on brands without UV/IR damage. You can not get that kind of protection with colored glasses or face shields. Switching speed used to be the big selling point before advancements in UV/IR protection at the light state. Taiwan, Switzerland, South Korea and Jackson Safety are the pioneers in AD filters making them easy to copy without doing a lot of initial research. That's China's angle

 

[vic4news]

I have a HF Auto-Darkening helmet and I did notice eye irritation when using it.
I switched to a Miller AD helmet and haven't experienced any discomfort.

Vic

 

[jmanatee2]

Also with any helmet, make sure you don't have a reflective surface behind you, the arc ray will reflect off the surface behind you and then off the inside surface of the lens into your eyes unprotected.

This can also occur if you are wearing light colored clothing.

I usually wear IR/UV safety glasses behind my helmet to help with reflected rays Also helps when I pick up chipping hammer or 4" grinder I already have safety glasses on so just tip up mask.

 

[Gary Fowler]

I just discarded an old HF helmet that I have used for about 3 years. It seems that my sweat dripping into the lens had got to the solar cell and shorted it out. It just suddenly quit darkening. On that helmet, there was no way to remove the lens from the helmet, only the front cover came off. I just picked up one of the other two HF helmets I had and continued with my welding project. I have never had any problem with flash burn (itchy eye you guys are calling it) with any of the HF hoods. This may be because I wear glasses under my hood, but I doubt darkening speed has anything to do with getting flash burn as the lens protects from that without the darkening effect. Most likely folks getting UV burns are getting reflective light from rear of hood or underneath the bottom that is bouncing in reflective light. ALWAYS wear dark clothing when welding, dont weld with light colored walls or shiny objects behind you. If you have to weld in reflective areas, put a cloth behind you kinda Arab style and that will block the light

 

[eastexan]

Also with any helmet, make sure you don't have a reflective surface behind you, the arc ray will reflect off the surface behind you and then off the inside surface of the lens into your eyes unprotected.

This can also occur if you are wearing light colored clothing.

I usually wear IR/UV safety glasses behind my helmet to help with reflected rays Also helps when I pick up chipping hammer or 4" grinder I already have safety glasses on so just tip up mask.

Most likely folks getting UV burns are getting reflective light from rear of hood or underneath the bottom that is bouncing in reflective light. ALWAYS wear dark clothing when welding, dont weld with light colored walls or shiny objects behind you. If you have to weld in reflective areas, put a cloth behind you kinda Arab style and that will block the light

Thanks guys. :thumbsup:
Some good points I wasn't aware of.

 

[Welshman]

I have a HF Auto-Darkening helmet and I did notice eye irritation when using it.
I switched to a Miller AD helmet and haven't experienced any discomfort.

Vic

Do you happen to know what the switching speeds are for either of these?

 

[tglass]

I'm in the market for an auto darkening helmet. I've spent a lot of time researching and looking, but the one aspect I'm not clear about is how fast is fast enough with regard to lens reaction time. The consensus seems to be that lens reaction time is more a matter of eye comfort (preventing "itchy eye") rather than eye safety (UV is filtered by the lens in its "at rest" state), but to me, there is a great deal of conflicting information. I've looked at expensive helmets that have a slower reaction time than less expensive helmets, and I understand that price difference can be the result of other factors, so my question specifically still is - How fast is fast enough? What are your experiences and/or data? Is there a "baseline" or minimum?
Thanks.

Something to remember, most helmets have a sensitivity setting for faster or slower darkening time. Some do not and will darken very fast. I've had the high priced helmets at work and after someone cleaned them the inadvertantly set it to slow reaction and light setting. Next novice to use it got flash from it and said the mask was no good. When I looked at the settings I saw the problem. Also the darkening setting may be set wrong. Wish there was a lock knob on them so I could not move it without knowing . At home I use the cheaper HF or Northern helmet, and have never had a problem with flash. Of coarse I'm the only user.

 

[Welshman]

Something to remember, most helmets have a sensitivity setting for faster or slower darkening time.

I thought, and I don't know, that the sensitivty adjustment controlled the "threshold" at which the lens darkens, rather than the speed of darkening. I know some helmets have a delay that controls when the lens lightens back up, but what is the point of slowing down the darkening? Wouldn't you always want it, once it starts, to darken as fast as its capability?

 

[yomax4]

Sensitivity is more of a Tig feature for 2 sensor Hoods. Some or most hoods have trouble picking up a Tig Arc because the torch is usually very close to the arc and often blocks it. You can make your lens more sensitive to darken when Tig Welding. However, Higher end hoods have 4 sensors and are able to pick up the Tig arc better compared to 2 sensor hoods like th HF ones and others. Another use for sensitivity is reflective arc from behind or sunshine from behind. You can turn it down to be less sensitive to reflective arc.