Get precise boiling range specs automatically . . . according to the new ASTM meth od for simulated distilfation by gas chromatography. Most chemists w h o have had to obtain boiling range distribution data on pe troleum fractions don't like any of the conventional methods because they are not very accurate, HP's new 7600A Gas Chromatograph System — w h i c h not only meets or exceeds all require ments for the new ASTM method for simulated distillation by GC but also completely automates it—puts an end to this problem. The 7600A produces results that are much more precise and reproducible than is possible with any conventional distillation method, w h e t h e r True Boiling Point (TBP), ASTM D-86 or ASTM D-1160. To test the repeatability of absolute retention times (thus boiling point dis
tribution) produced by the 7600A, 19 runs were made from separate vials of a calibration mixture of normal par affins whose boiling range is - 4 4 ° F to 928°F. The results are shown in the photograph below. Reproducibility of the data is e x c e l lent across the entire range. The most c r i t i c a l t e s t of r e p e a t a b i l i t y is t h e spread between t h e maximum and minimum values for each of the c o m ponents. In all cases, the spread is amazingly small. Even in the worst case, the spread is only 0.25 minute for a peak whose retention time was 31 minutes. The worst standard devia tion is 0.080. The 7600A operates completely un attended for as many as 36 consecu tive samples of widely different boiling ranges. It includes complete sets of programs for automatic data reduc
tion, calculation and reporting of re sults: any of the principal time-sharing computer services or a dedicated HP mini-computer can be used. An analy sis report of boiling range distribu tion in 1 % increments is prepared automatically in less than an hour, for less than 5 dollars per sample, includ ing all costs. For complete information and a copy of the new ASTM method, call the nearest HP sales office, or w r i t e : Hewlett-Packard, Route 4 1 , Avondale, Pa. 19311. In Europe: 1217 MeyrinGeneva, Switzerland.
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