ADF’S (Auto Darkening Welding Filters) 

While the welder is performing weld, his safety is key factor. So, he must be provided with appropriate safety equipments. One of them is the use of Darkening Filters for protecting his eye sight; most convenient is the Auto Darkening Welding Filter. As an Auto Darkening Welding Filter, lens or glass is used.

1)    Introduction :

The first Auto Darkening Welding Filter was introduced in 1981. Before the Auto Darkening Welding Filter, helmets with tinted glass were used to prevent eye sight of the welder from welding spark lights but when arc vanishes then without removing that tinted glass helmet welder was unable to view welding spot clearly for observing weld quality and for proceeding weld from same spot. Consequently, welder was unable to perform smooth and better quality weld.

 The Auto Darkening Welding Filter was then introduced and it removed that problem of removing the helmet repeatedly and darkens the spark light automatically and automatically switches to normal position when arc vanishes. This feature of Auto Darkening Welding Filter helps welder in viewing the welding spot clearly without problem of removing helmet repeatedly for clear view of welding spot.

2)    Structure :        

Auto Darkening Welding Filter comprises a multilayer complex structure. In an Auto Darkening Welding Filter, there is a protective layer of lens, behind this there is a filter which protects from ultraviolet & infrared light and behind this, there is another filter known as liquid Crystal Display filter. Auto Darkening Welding Filter has a shade adjustable system, which allows us to adjust shade for controlling the intensity of arc depends on type of weld.

3) How Auto Darkening Welding Filter works:

When the welder is not performing weld, Auto Darkening Welding Filter remain in normal position in which you can see any object clearly. But when spark light occurs from arc, The Auto Darkening Welding Filter senses it within the fractions of second more faster than our eye blinks and activates the darken state of the lens. Then it reduces intensity of spark light and prevents the welder from harmful effects of spark light on eyes. As soon as arc stops, Auto Darkening Welding Filter automatically switched to normal position which allows welder to see welding spot clearly and make it easy for him to make a next weld from same spot. Also help him to position the welding rod, torch accurately.

4)    Types of Auto Darkening Welding Filter:

There are two main types of Auto Darkening Welding Filter and are given below:

·         Battery Powered

·         Solar powered

Those which are operated by Battery are convenient while you are working indoor e.g. in workshops etc. Solar powered are convenient while you are working outdoor e.g. in fields etc where you have an exposure to sunlight.

5)    Superior to Passive Lenses :

Auto Darkening Welding Filter is superior to passive Lens because of following reasons:

·         It is more efficient, about 30 % more than passive lens

·         It switches automatically to normal/clear position thus removes the problem of removing helmet repeatedly to observe welding quality and position the rod or torch.

·         It helps in producing smooth and high quality weld as it makes the welder enable to view and focus the welding spot clearly without removing helmet.

6)    Draw Backs :    

Auto Darkening Welding Filters have the following Draw Backs:

·         They are more expensive than passive lens