National Bureau of Standards, 3 GEE Cal test

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The discussion centers on the "3 GEE test," a calibration procedure used in the early 1970s for electronic and frequency generation standards, particularly before certifying equipment as traceable to the National Bureau of Standards (NBS). The test involved elevating one corner of the equipment to create a force equivalent to three gravities, then dropping all corners sequentially to assess calibration accuracy. The equipment had to maintain a calibration variance of no more than ±0.1% after a stabilization period. This test was not intended to measure durability but rather the reliability of calibration traceability. The test has become less common due to advancements in solid-state technology. The NBS has since been replaced by the National Institute of Standards and Technology (NIST), complicating the search for historical references on such tests. The discussion also touches on the potential relevance of the test to accelerometer calibration and impact testing, with a suggestion to contact an expert for further information.
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In the early 70's, while in the US ARMY, I attended USAOC&S at/in Aberdeen Proving Grounds for the then NBS sponsored 44 week long (8 hrs/day for a full yr) school in calibration. One test we performed on specified CALIBRATION STANDARDS for tracability was called the "3 GEE test".

Can anyone tell me what this entailled, without my prompting, to prove to my smart-A son-n-law and self proclaimed "computologist" genious of its existence, purpose, and general usage.? <please>

Thanks to all, I've never posted anywhere but love the sometimes highly stylized manners in repudiation...love it!

Moses Mann
Utah
 
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Is this a brain teaser ?
:confused:
 
3 GEE test

Kittel Knight said:
Is this a brain teaser ?
:confused:

In the same manner as "Rubick's Cube" titles the puzzle, so too does "3 GEE" title this real life puzzler.

moman
 
As others have probably already noticed, Googling "3 GEE test" gives one hit -- this page.
 
I guess my three Gee test question lost favor and flavor.

The three GEE, or 3G as it was referred to in 1973 by the old NBS, was one of the last tests performed on electronics and frequency generation standards prior to placing a sticker of certification of calibration traceable to the National bureau of standards. It was only used on standards and not general use test, repair, and operational equipment [field usage] .

Basically, once tweeked to spec, the equipment would be elevated at one front corner sufficient to produce three gravities [HENCE "3GEE's} of impact force, about 4 fingers or 2.5 to 3" on a flat granite mass of 500kgms or a solid cement floor known to be > 6 inchs with no crackswithin 6 yrds. All 4 corners were dropped sequntially, thusly, and checked after each drop, and the constancy of accuracy of the calibration could not vary +/- 1/10th of 3% of full scale, or exceed any spec after a 15 minute stabilization period.

Most "A" level standards had to be mounted with a "rolling-pin" device that would allow it to be rolled of for the free fall testing.

Today, the test is rarely used because of solid state components and sophisticated IC and Field Effect components, and tubes used only to maintain a required heating constant with conjuction with heat sinking.

This test was NOT A DURABILTY NOR TUFFNESS, RIGIDITY, OR FAILURE RATES TEST AKIN TO CONSUMERS REPORTS, ONLY THE RELIABILTY OF TRACEABILTY.

This is only the briefest of the tests performed, but gives general albeit not exact details.

Hope you get to try it some day. Today, NBS, the UNITED STATES ARMY CALIBRATION AND STANDARDS CORPS NO LONGER EXIST AS FORMALLY CONSTITUTED which makes finding references difficult to find.

Enjoy your new knowledge and understanding on the way things used to get done.

Moses Mann
Utah
 
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NBS was superceded by NIST. Good luck in finding information about NBS tests from the 1970's or earlier.

Was the 3g test for calibrating an accelerometer? Was it related to impact testing?

NIST offers calibration services over a range of accelerations (g's), but nothing sounds like the '3 g test' described above.

One guy who might know, or possibly know who might is Patrick Walter.
http://www.sandv.com/downloads/0701walt.pdf
contact email on bottom of last page.
 

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