Visual Fault Locator

[Metryq]

I just picked up a visual fault locator (VFL) for fiber optic work, and I have some questions about the device.

I realize the unit is meant to attach to the end of a fiber via its "universal" connector. However, when aimed at a surface a meter away, it produces a "rosette" pattern about 30cm in diameter, rather than a focused dot. Is this normal? Is it deliberate to diffuse the light around the interior of the fiber?

The label is very bizarre. It says "invisible laser radiation," yet it is a visible red laser. Does this use a DPSSL type arrangement? The warning label also states "excimer laser" :wtf: and "class I laser product."

That "class I" rating also confuses me because the label next to the warning tag states that the frequency is 650nM (red) and—get this— "P≥25mW". Greater than, or equal to? Not if it's class I.

 

[Gadget]

Yes it is by design that the beam is diffused. It makes it easier to see the fault if the beam is bouncing around inside the fiber, so it can exit the fault easier.

-G

 

[Metryq]

Thanks, Gadget. I just wanted to be sure it hadn't been bounced in transit.

Any ideas on that wacky labeling?

 

[crazyspaz]

Is it from China?

 

[Metryq]

China? Probably, but I've seen no such markings. The primary label is black with white text and wraps around the entire head of the device, interrupted only by the slide switch. The serial number sticker—with the frequency and wacky power rating—is laid over the black label. So it's possible that upper sticker covers a "Made in China" notice.

I'm not all that worried about the precision of the unit. How precise does one have to be to make a VFL? It's a glorified flashlight.