Mechanized Use of Spectral Indexes

Baker et al. (1953) and Kuentzel (1951) have described machine methods of forming spectral indexes. The ASTM has adopted (1958) the Kuentzel method, which is the basis for the Termatrex and various computer methods. 

An IBM card sorter is needed for searching through the deck of cards. Each characteristic of the spectrum to be matched requires a complete run-through of the cards. Since this can be a difficult and time-consuming task, many workers presort their cards into piles, one pile containing, say, all ketones, another all hydrocarbons, another nitrogen only. 

The process of elimination can be a strong tool here. One looks for all the cards on which a certain characteristic is missing. For example, if a substance displays no band at 7.3 /i, one can remove all cards having a band at 7.3 /t and thus leave fewer cards remaining to be searched through. 

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