Dating a chemical slide rule by atomic mass data

The table of atomic weights on the back of some chemical slide rules can be used to date these slide rules, assuming the manufacturer used the most recent International Comittee (IUPAC) values.

This tools helps you to date a chemical slide rule.
You can do two things:

Select a pre-defined slide rule, and check its dating.
Select -your slide rule data-, enter the masses of the elements found on your chemical slide rule and click Refresh to check its dating.
If you want to submit this data, specify its name of your slide rule and Mail data (this will use your email program and exposes your email address to the author of this page)

The results are depicted in colors:

(bold green)	IUPAC mass corresponds to the atomic mass on your slide rule.
(yellow)	All IUPAC masses for this year correspond to the atomic masses on your slide rule.
(less yellowish)	All but one IUPAC masses for this year correspond to the atomic masses on your slide rule.
(even less yellow)	All but two IUPAC masses for this year correspond to the atomic masses on your slide rule.
(grey)	You did not specify an atomic mass for this element.

Your slide rule name:

Data from "History of the recommended atomic-weight values from 1882 to 1997: a comparison of differences from current values to the estimated uncertainties of earlier values", Pure Appl. Chem. 701 1998 237-257 [https://www.iupac.org/publications/pac/70/1/0237/index.html]
K=39.104 : Hönigschmid and Caubeau, 1928

Peter Hopp, "Slide Rules - Their History, Models, and Makers", The Astragal Press, 1999 dates the Nestler 33 from 1915–1955, and first mentions the Nestler 0330 in a ca.1967 catalog. J�rgen Bartzik dates the Nestler 33 from 1912–1955.

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Andries de Man, Jan 2007, update Aug 2019