How to tell if a UV lamp is working?
 

How can one safely tell if a UV lamp is working? This is a UV tube in
a pond filter system which lives in a lightproof (well, UV proof I
suppose) tube with the water going to the filter flowing past it.

It has standard fluorescent gear, a choke and a starter.

--
Chris Green

How to tell if a UV lamp is working?
 

In article ,
writes:

How can one safely tell if a UV lamp is working? This is a UV tube in
a pond filter system which lives in a lightproof (well, UV proof I
suppose) tube with the water going to the filter flowing past it.

It has standard fluorescent gear, a choke and a starter.

Often they have a little fluorescing plastic indicator in the
case, to show it is picking up UV. You should change the tube
annually anyway (assuming 24x7 operation), as UV output drops,
and in continuous operation the output will become too low before
the tube fails in the conventional ways (i.e. not starting).
If you are doing this and the unit is drawing roughly the right
current, I would assume it's working unless you have some other
reason to suspect it (e.g. pond going unexpectedly mankey).
When operating, it may generate some ozone which you might be
able to smell from the casing, but they don't all do this.

I hope the unit has interlocks to prevent you looking at the
tube operating, which is dangerous. However, if you are tempted
to try defeating the interlocks, put a sheet of glass (not
plastic) between you and the lamp, stand well back, and only
operate the lamp for a few seconds. There is normally a dim
visible glow from the clear tubes.

--
Andrew Gabriel

How to tell if a UV lamp is working?
 

On 08 Oct 2006 09:12:47 GMT, wrote:

How can one safely tell if a UV lamp is working?

Is it interlocked not to come on if the box is open? Defeat the
interlock, probably just a switch on the cover then in a dark area switch
on and see if a sheet of ordinary white photo copier type paper
fluoresces. You may also see a dim blue glow. Obviously don't stare at
the tube or spend any longer than required exposed but a second or three
isn't going to hurt you.

--
Cheers
Dave. pam is missing e-mail

How to tell if a UV lamp is working?
 

Andrew Gabriel wrote:
In article ,
writes:

How can one safely tell if a UV lamp is working? This is a UV tube in
a pond filter system which lives in a lightproof (well, UV proof I
suppose) tube with the water going to the filter flowing past it.

It has standard fluorescent gear, a choke and a starter.

Often they have a little fluorescing plastic indicator in the
case, to show it is picking up UV. You should change the tube
annually anyway (assuming 24x7 operation), as UV output drops,
and in continuous operation the output will become too low before
the tube fails in the conventional ways (i.e. not starting).
If you are doing this and the unit is drawing roughly the right
current, I would assume it's working unless you have some other
reason to suspect it (e.g. pond going unexpectedly mankey).
When operating, it may generate some ozone which you might be
able to smell from the casing, but they don't all do this.

I hope the unit has interlocks to prevent you looking at the
tube operating, which is dangerous. However, if you are tempted
to try defeating the interlocks, put a sheet of glass (not
plastic) between you and the lamp, stand well back, and only
operate the lamp for a few seconds. There is normally a dim
visible glow from the clear tubes.

Thanks, we have two spare tubes (it's ex. my mother-in-law) and I
doubt very much if the tube has been replaced within living memory so
I'll change it anyway.

--
Chris Green

How to tell if a UV lamp is working?
 

"Andrew Gabriel" wrote in message
...

I hope the unit has interlocks to prevent you looking at the
tube operating, which is dangerous. However, if you are tempted
to try defeating the interlocks, put a sheet of glass (not
plastic) between you and the lamp, stand well back, and only
operate the lamp for a few seconds. There is normally a dim
visible glow from the clear tubes.


I would have thought most plastics would block UV more than glass. Most UVB
and almost all UVC are blocked by virtually any material apart from quartz.

How to tell if a UV lamp is working?
 

wrote:

How can one safely tell if a UV lamp is working?

You can't (without vast expense) -- output falls with time, so
bactericidal UV lamps are time-rated. I'm not sure about algae though?

As to a simple "Is it still working electrically" then they nearly all
have visible glow too. If you can't defeat the interlocks, then stick a
piece of phosphorescent plastic in there and see if it's charged up by
it. It's nearly Hallowen, I'm sure you can find some glowing vampire
teeth.

How to tell if a UV lamp is working?
 

In message ,
writes

How can one safely tell if a UV lamp is working? This is a UV tube in
a pond filter system which lives in a lightproof (well, UV proof I
suppose) tube with the water going to the filter flowing past it.

It has standard fluorescent gear, a choke and a starter.

White material especially after having been washed should fluoresce when
exposed to the light

that's all I can say

--
geoff

How to tell if a UV lamp is working?
 

On 2006-10-08 10:12:47 +0100, said:


How can one safely tell if a UV lamp is working? This is a UV tube in
a pond filter system which lives in a lightproof (well, UV proof I
suppose) tube with the water going to the filter flowing past it.

It has standard fluorescent gear, a choke and a starter.

That's a tough one.

I have something similar used as a steriliser for a reef tank.

The problem is that they don't suddenly stop working, but rather the
output degrades.

Generally, therefore, one replaces them according to time - mine is
changed every 6 months.

For a pond system where the UV is usually used to control algae, one
could look on the basis of whether the algae is being controlled.
However, as you probably know, algal growth depends on sunlight,
temperature, nutrient availability and your inside leg measurement, so
it is not always easy to make an assessment of whether the UV treatment
is doing its job.

How to tell if a UV lamp is working?
 

raden wrote:

White material especially after having been washed should fluoresce when
exposed to the light

It really needs to phosphoresce though (e.g. zinc sulphide), not
fluoresce (e.g. washing powders). Fluoresecence is immediate,
phosphorescence has a time delay.

If you could see something in the act of fluorescing you'd probably be
able to see the blue glow. Phosphorescence allows you to open it, close
it, put the power back on, open it up and then see afterwards if it had
illuminated.