DI vs. Distilled

[mixedgas]

Eric, Laserscope typically used a color indicating DI filter material.. Are yours dark greyish black (usually good or unexpended) or a light Orange-Brown( typically Expended) ?
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www.spectrapure.com for good ones.
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At .15 ma, the clips take a very, very long time to degrade, but they still will degrade.
At 1-2 mA, degradation is rapid.
Dying spider clips first turn a green or turquoise color, where they should be a bright gold. Then they turn grey/black and the lamp will probably die. The spider clip is usually mounted inside a larger clamping clip or a metal block depending on the lamp mount. The spider clip is hot and has cavitation going on around it, so it is the most vulnerable.
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The hiss is hard to hear over the pump. If you have good hearing, your head needs to be within about 18 inches of the lamp cavity, which is of course not recommended safe procedure (Danger, Lethal High Voltage, Danger, Blinding scattered IR and Green light)
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Steve

[planters]

Thanks Steve. I'll check.

[Photonbeam]

Learned something new from Steve's post #9. I always thought that sizzling sound from the LS cavity was boiling. So it's electrical?!

[mixedgas]

Sometimes it's electrical. All I know is it drastically quiets down when the DI is good. There is always a hiss, but you can really tell the sizzle when it's full of ions.

Steve

[mixedgas]

I didn't learn about this until restoring my friend's 800 last year.

[Draco]

one place i worked at had there own DI system for washing medical disposable products and we used it for cleaning circuit boards and had to warn people to not drink it or put it there cars, the system did have a tap before the DI cartage's.
this thread has explained why i see so much corroded crap on fleabay, i have a meter for TDS but i don't know if it will give me the resistance of the water, maby one day i will venture into water cooled stuff but i am still just playing with flash lamps that are air cooled.
I do find that a lot of people are surprised that water can have a very high electrical resistance and i have a question that may be off topic but for the values you guys are using, say 18 meg, is that for a certain volume of water? or the entire length of the cavity it will be in?

[planters]

This is an interesting topic. You might want to read up on it.

To summarize, super pure water is so devoid of foreign ions that it will pull them out of just about anything, even clean glass and plastic and that is why you can't store the purest water for more than a couple of days. The absolute limit is just over 18 meg ohms PER CENTIMETER and that is in completely de-oxygenated and degassed water. If you open the water to the atmosphere the small quantity of CO2 that is absorbed will reduce this number by nearly half.

The reason that the resistance isn't any higher than 18 is the equilibrium dissociation of the H+ and OH - ions.