NukeWorker Forum

News and Discussions => History & Trivia => Topic started by: mostlyharmless on May 29, 2009, 07:35

Title: 100cm2
Post by: mostlyharmless on May 29, 2009, 07:35
Where did the standard of 100cm2 come from and how long have we been using it?
Title: Re: 100cm2
Post by: X-Nuke on May 29, 2009, 08:29

Well, at the risk of showing how little I know, I'll go with it being roughly equal to the size of a dollar bill (and makes the math easier too) and in use since the 1940s.

Bill
Title: Re: 100cm2
Post by: Motown homey on May 30, 2009, 05:58
I remember that they told me in ELT "C" school that there were three criteria: 1) It's easy to do - two fingers on a smear dragged 16 to 18 inches (usually in an "S" pattern).  2) Dragging a filter paper smear much further tends to deteriorate the smear and you start to lose sample.  3) It's a nice round number.
Title: Re: 100cm2
Post by: Adam Grundleger on Jun 01, 2009, 11:28
If I remember correctly, in ELT school they taught us it was large enough for a representative sample but small enough that the swipe would not come apart.  I wouldn't doubt the round number is for radcon math.  The limits are also written to 100sqcm, though I'm sure that's based on the sample size. 
Title: Re: 100cm2
Post by: SloGlo on Jun 01, 2009, 09:54
bean a factor of tenn, it makes alla math sew much easier.  peek oh curies work best two.  gist axe enny buddy dat went threw oral boards.   ;)
Title: Re: 100cm2
Post by: HydroDave63 on Jun 01, 2009, 10:57
There once was a time before 100cm2...

(http://www.orau.org/PTP/collection/radiac/10Aface.jpg)

Saw one of these for sale on eBay last month, the venerable old AN/PDR-10A
Title: Re: 100cm2
Post by: SloGlo on Jun 03, 2009, 08:48
Quote from: HydroDave63 on Jun 01, 2009, 10:57


Saw one of these for sale on eBay last month, the venerable old AN/PDR-10A

'n shorely won of da shortest usage times for a military radiac instrument....
mebbe 150cm2 area corfuzt two manny peepul?
Title: Re: 100cm2
Post by: HydroDave63 on Jun 03, 2009, 08:54
Quote from: SloGlo on Jun 03, 2009, 08:48
'n shorely won of da shortest usage times for a military radiac instrument....
mebbe 150cm2 area corfuzt two manny peepul?

in those days, 4"x6" photos were still common, and a 4x6 is darn close to 150cm2

100cm2 is ~ 3"x5" , which has been common as well, any coincidence?  ;)
Title: Re: 100cm2
Post by: SloGlo on Jun 03, 2009, 09:11
Quote from: HydroDave63 on Jun 03, 2009, 08:54
in those days, 4"x6" photos were still common, and a 4x6 is darn close to 150cm2

100cm2 is darn near 3"x5" , which has been common as well, any coincidence?  ;)

no wing hour gubbermint prefurs a thousand words over a worthy picture, eye wood say..... no.   ;)