Auto Darkening Lens Reaction Time

[yomax4]

Worst case, If you burn your eyes while welding., Squeeze Potato juice in them and they will recover within a few hours (with damage done). Or see a Dr. And he will numb them for you. In any case the pain only lasts one night but sucks badly.. As for adjusting switching time, I have never seen a lens that allows adjustment to switching speed. Sensitivity is only that, Adjusting how sensitive the sensors become to the Arc. When the Arc starts your lens should switch. If not, There is a problem.. This may be another case for buying a higher end brand.
If I burned my eyes with any hood, I would pitch it!

 

[yomax4]

Two years ago I experienced a rather severe eye burn after having gotten my first auto-darkening helmet and not fully understanding all of the adjustments it had or where I needed them to be.

I spent a little bit playing with and it seemed to work perfectly fine and seemed to darken/lighten instantly upon arc to the naked eye. So I proceeded to do a couple hours worth of welding with my new helmet just thrilled at what a better welder I had become with it not realizing anything was wrong. A couple hours later I thought I was experiencing a sudden bought of allergies as my eyes got all irritated and were watering terribly. Then they began to hurt rather badly it hit me what had happened. Didn't have the new helmet adjusted to the correct reaction speed and every time I struck an arc the lens delayed momentarily allowing a minute burst of light through to my eyes but it was not noticeable to me. I dialed the sensitivity up since and haven't had a problem again.


Not fun though. Eyes feel like they're full of sand and you can't get it out. Spent several days afterward stuck in the house with all lights off, shades drawn, tv/computer dimmed way back, and wearing sunglasses until my eyes healed themselves back.

Strange. Normally Delay only keeps the lens dark longer after you stop the arc so the puddle can freeze so you don't have to look at the molten metal.. Maybe want to get rid of that hood.

 

[JoeinTX]

Yep, did the potato thing that evening for several hours. Hash browns worked best for me I found.

Funny thing was that my dad (30-odd years older than me) used that hood for an hour or so that same day as we both played around with it on a few little projects to try it out and had zero effects. Doctor told me that older eyes are less sensitive to such things explaining why I got burned and he didn't.

It's one of the automatic Hobart models with replaceable batteries that TSC sells. Can't recall the model at the moment as it's not in front of me.

 

[Welshman]

Is it one of the variable shade models? It seems like the problem was more likely caused by too light of a shade, rather than sensitivity or lens reaction speed, doesn't it? Glad to hear you're alright - that would have scared the heck out of me.
On a related subject: I bought a #10 "gold" coated lens for my regular helmet a couple of weeks ago. Now I read in my "Welder's Handbook" - "Don't use gold and silver-plated lenses. Although they are pretty, one tiny scratch in the gold or silver plating could admit enough ultra-violet light to burn an eye". Can this be accurate? I thought the "plating" was a glare reducing addition, not the sole protection. Anybody know?

 

[yomax4]

If I wasn't using an AD filter I would use Gold. The ones i used to sell were various shades like the regular filters but the Gold was just a reflective overlay. Used them for years before the AD hoods came out. Never had a problem from scratches. Can't speak for all brands though. Back in the day, Lincoln used to offer a Blue lens that had a cool look when you welded with it.

 

[Welshman]

Thanks, Yomax. This lens is a Hobart so it's probably good quality.
What is the "procedure" with these variable AD helmets, as far as darkening setting? Just set it based on a lens chart, and adjust as needed?

 

[Scooby074]

Is it one of the variable shade models? It seems like the problem was more likely caused by too light of a shade, rather than sensitivity or lens reaction speed, doesn't it? Glad to hear you're alright - that would have scared the heck out of me.
On a related subject: I bought a #10 "gold" coated lens for my regular helmet a couple of weeks ago. Now I read in my "Welder's Handbook" - "Don't use gold and silver-plated lenses. Although they are pretty, one tiny scratch in the gold or silver plating could admit enough ultra-violet light to burn an eye". Can this be accurate? I thought the "plating" was a glare reducing addition, not the sole protection. Anybody know?

i like the gold lenses. prior to my AD that was what i used. Alot of the old timer welders swear by them.

Remember that the lens is sandwiched between 2 clear pieces of glass (or plastic). It should remain scratch free for a long time.

 

[yomax4]

Thanks, Yomax. This lens is a Hobart so it's probably good quality.
What is the "procedure" with these variable AD helmets, as far as darkening setting? Just set it based on a lens chart, and adjust as needed?

I usually like to set sensitivity at or near Max. Delay about 1/2 depending on how thick the material is that you are working with. Then it's what ever shade you require. Some welders like shade 9 and some like shade 12. Standard is 10 but super thin material may require a 9. 1/16 hard wire on Pulse may require shade 11. Choose 10 as a start and let your eyes tell you the rest. If they get irritated. Go darker or you may need a cheater lens.

 

[CalG]

A previous post alluded to the sensing mechanism of AD welding shields, but please TAKE NOTE:

The auto darkening sensing device of a quality AD welding shield is triggered by the emission spectra of the arc ionization path PRIOR to an arc being generated.
The mechanics of an arc require a "conductive path" before any current will flow. Ionized "air" provides this means of electron mobility. Just as in the case of a lightening strike.

So, if there is a "delay" between sensing and darkening, the timer starts "in the dark"!

The reaction time for the AD effect will also include the time it takes for the Liquid Crystal to orient it's molecules to the darkened position. A very small amount of time indeed, but could easily become part of any manufacturers "Specification".


(Cheap helmets may use photo sensors, but it is just wrong if they do. You get what you pay for)

2cents

 

[flusher]

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.

Yep, reflected UV is generally the cause of eye itch. That and light leaks around the helmet window. To block this out I wear tight fitting yellow tinted UV filtered polycarbonate (Lexan) motorcycle goggles rated at UV400 under my AD helmet. Cost $7/pair at Amazon.com.

Global Vision Eyewear - Wholesale - Eliminator Lens AST