Question about UV Scanners (tubes)

I have a few Fire-Eye 45UV5 scanners (model 1009). I reseated the tube in two of the units, and am wondering if the oil from my skin could possibly cause the reading to be lower (about 1.00VDC lower than previous readings).
If so, would isopropyl work, or just a clean cloth?


thanks...

From http://www.sqpuv.com/linear/uvsafety.html...

"Lamp must be wiped with alcohol before placing in service. Bare skin contact with the quartz envelope must be avoided. Compounds from the skin when heated on lamps operating at 600- to 8500C will form permanent etching (devitrification) on the quartz surface decreasing UV energy transmission. A contaminated lamp eventually will overheat causing premature failure that will not be covered under warranty."



-Eric

I use a lens cleaner for cameras... I have also heard that it shortens the life (if you touch it and leave the oil on it)

Disclaimer...I have not read Eric's link yet, so I may be full of **** again

I'd throw the tubes out and start again (if they've been running more than 2 minutes they're already ruined).

NEVER, ever under any circumstances use a lamp/tube that has been touched by bare hands. In the past I've seen tubes explode because of uneven heating caused by oil etc from the skin.

Alcohol (hmmm it's Friday I am already thinking about beer!) or something alcohol based is probably the best cleaner. I've never personally used isopropyl but I can imagine it would work ok, but bear in mind that the damage has probably already been done.

Thanks everyone for the feedback. However the tubes are fine.

A UV scanner senses uv. They don't generate heat.

I was finally able to get through to Fire-Eye, their phones have been working intermittently it seems, and got the 411. lol


A soft cloth will do fine. Over time the oils can degrade the quartz, but short-term exposure is not an issue. The reason for the slightly lower reading is probably due to the tubes orientation. I didn't realize it at the time, but I probably moved the element inside the tube slightly off parallel to the burner. By doing that it reduces the surface area exposed to the uv generator, and therefore causes a reduction in signal strength.

Tomorrow morning I'll take care of it. No biggee.

I put some trap logic to check the burner status and so far there haven't been any failures since the logic was put in (Wednesday).

Keeping my fingers crossed.

I pull mine about once a year, clean the shutter (if you have one) and also clean the tube and adjust the pilot flame...

I have never heard of them exploding, but if the did there inside the burner, now I have seen a explosion (complete incinerator) and one melt down (a boiler)...not good

I did a lot in the past with sodium light assembly machines for a big company whose name begins with G and E.

The operators were very careful to handle the tube components with cotton inspection gloves. They always said the oils from your hand screwed up everything.I didn't touch anything, so I stayed out of trouble.

I would assume any glass or glass-like (quartz, etc.) tube is susceptable to the same potential problems.

My two cents.

geniusintraining said:

I pull mine about once a year, clean the shutter (if you have one) and also clean the tube and adjust the pilot flame...

I have never heard of them exploding, but if the did there inside the burner, now I have seen a explosion (complete incinerator) and one melt down (a boiler)...not good

Click to expand...

The exploding lamp was in a curing oven, apparently the maintenance guy changed a lamp out during the night. My guess would be that it wasn't just oil from his hands but maybe a greasy rag? Anyway the resulting pop was pretty loud with plenty of glass managing to find it's way out of the shutter!
But this was many many moons ago!

Russ said:

The reason for the slightly lower reading is probably due to the tubes orientation.

Click to expand...

Does your unit have a reflector?

The units we use have a reflector to focus the light at a specific point. In this case, the orientation between the tubes and the sensor will be critical.

Another thing to consider is the condition of the reflector. In the past we have inspected ours and thought it's condition was fine until we compared it to new one.


In other discussions..... I've worked in this facility for 19 years, I've seen one tube explode of 6 units running 24/7. I've seen 1 unit melt down. (not pretty) We've since taken control measures to prevent that from happening again.

IO_Rack said:

Does your unit have a reflector?

The units we use have a reflector to focus the light at a specific point. In this case, the orientation between the tubes and the sensor will be critical.

Click to expand...

Yes it does. That's actually what I'm going to be setting the orientation of the electrode to.

IO_Rack said:

Another thing to consider is the condition of the reflector. In the past we have inspected ours and thought it's condition was fine until we compared it to new one.

Click to expand...

I've checked the condition of the reflectors in bright sunlight and they look to be in good shape.

IO_Rack said:

In other discussions..... I've worked in this facility for 19 years, I've seen one tube explode of 6 units running 24/7. I've seen 1 unit melt down. (not pretty) We've since taken control measures to prevent that from happening again.

Click to expand...

Some unit's I've worked on used combustion air to keep the scanners cool. It's cheap, easy to set up, and does the job pretty well.
However there is around an 8" nipple from the site glass on the burner to the mounting for the fire-eye's. It's a pretty significant distance for the heat to migrate. Plus I've instructed the plant that whenever power is lost (which is essentially the only time the combustion blowers won't be running) to remove the scanners from the burners.
I'd rather error on the side of safety. The mauv1s are much more tolerant of heat than their shuttered counterparts. Plus the parts they use to build the 45uv5s aren't quite.... ummm... 'top notch'.. if you know what I mean...