At 09:57 PM 1/25/03 -0600, Dan Minette wrote:
> > Must be more stringent than the specs for the NaI(Tl) crystals and PM tubes > I recall from the unclear lab, or PM tubes used in astronomy. Although > fortunately I haven't actually tested any of them for impact resistance . . .Very much so. Designing packaging to meet those tolerances is a tremendous challange: especially when it is 20 g rms at 175C. A lifetime test for areospace is considered light qualification screening for MWD.[1] Dan M [1] I should probably define this for new folks on the list. MWD is Measurement While Drilling (oil wells).
So I assume 175�C (448K) is considered normal operating temperature in the MWD case? In the lab, we used liquid N2 (77K) to cool the detectors, for photometry at the telescope, we frequently used dry ice (196K) to make things more sensitive and cut down on false counts due to random thermal events. Either one makes things kinda brittle compared to room temperature . . .
GSV Ever Seen A Goldfish Submerged In Liquid Nitrogen Then Dropped On The Floor (Oops! . . . E-Yuck!!! Class)
ROU Then There Was The Student At The U Of Alabama Who Thought It Would Be Neat To Take Some Liquid Nitrogen Back To The Dorm After Lab In A Glass Bottle In His Pocket
--Ronn! :)
I always knew that I would see the first man on the Moon.
I never dreamed that I would see the last.
--Dr. Jerry Pournelle
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