[time-nuts] Man killed in quartz crystal accident

Bill Hawkins bill at iaxs.net
Sun Nov 24 19:00:22 EST 2013


This is not as far from time-nutty things as it might appear.

NDK makes precision crystal oscillators from those crystals. One of them
is an OCXO less than an inch (20 mm) square and half that high with
stability of 3x10E-9 over the range of -40 to 85 C. Annual drift is
typically 50x10E-9. The data sheet is at:
http://www.ndk.com/en/news/2013/1190702_1616.pdf

The CSB released an impressive video of the incident last month. It is
in the final report at:
http://www.csb.gov/ndk-crystal-inc-explosion-with-offsite-fatality-/

The financial forecast for NDK shows 50 to 60% drop in profits for the
same sales in 2013. If that was also true in 2009, management was
motivated to maximize production with what they had. The original
consultant strongly recommended inspections for stress corrosion
cracking, but strong recommendations do not have financial penalties. It
has become obvious that money is the only thing that matters at the
management level these days.

Oh, and don't bother trying to Google for "pure quartz crystals" to find
out whether the cost went up in 2010 after one of the two manufacturers
in the US was shut down. The people whose magical thinking extends to
crystals want purity, so all crystals are "pure."

Help prevent incomplete knowledge.

Bill Hawkins


-----Original Message-----
From: Robert Atkinson
Sent: Sunday, November 24, 2013 1:43 AM

The US Chemical Safety Board have released their report into the 2009
accident at NDK's synthetic crystal growing facility in Belvidere IL <
http://www.csb.gov/assets/1/19/CSB_CaseStudy_NDK_1107_500PM.pdf > It
also describes the process.

Basically a 50ft autoclave failed, killing a member of the public at a
rest stop 650ft away. Looks like management decisions, probably based on
cost, overriding engineering advice even following an earlier minor
incident. The letters from a consulting engineer in the annex make
interesting reading. It illustrates the importance of those professional
engineers amongst us notifying and recording any safety issues we
discover. The facility is still shut down and the insurance company
won't settle as NDK were told of possible issues.

Robert G8RPI.



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