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Message ID: 107     Entry time: Fri Jan 23 16:48:29 2009
Author: Dmass 
Type: Laser 
Category: PSL 
Subject: Chiller noise and DeI water 
John Miller emailed me about the chiller once again whining. The water level was almost at the "min" line, and he filled it. This appears to not have been the culprit for the alarm. The screen on the chiller read "filters" and the noise stopped when I touched a button. The light in back which turned red when the water started to fail the deionized test is still red.

To my knowledge the following is the story

The new chiller wants Deionized water. It has brass fittings in it's plumbing, and by 40m lore, we do not mix brass fittings and deionized water - also Peter King said that it would be ok to use distilled water - I filled it with distilled water, and after a few weeks of stable operation (no noise or leaks) the red light on the back of the chiller went off (which I believe is triggered by the resistance of the water dropping too low). The high pitched whine of an alarm noise would periodically come on, and I would periodically turn it off. After this last time which I was notified of ~1 week ago by John Miller, the readout on the chiller said "filters" instead of "dei". I do not know how much attention we should pay to the purity of the water, and we may want to look into disabling the alarm if we continue using distilled water with the deionized water system.
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