Finally, someone built a medium price gas chromatograph that performs like our Model 900. We didThe Model 990.

Circle No. 137 απ Readers' Service Card

58 A · ANALYTICAL CHEMISTRY, VOL. 42, NO. 1, JANUARY 1970

If you work in gas chromatog­raphy, you probably know our Model 900. It's the best-perform­ing and most versatile gas chro-matograph on the market.

And, naturally it costs a little more. So for budget reasons some people had to settle for something a little less.

But not any longer. Now, if you can get by without just a few of the extras, our new Model 990 gives you exactly the same high performance. For substantial ly less money.

In fact in re-design we even made a few improvements. A new

parametric amplifier that's inher­ently more stable. And new solid-state all-electronic timers.

As with the Model 900, the 990's oven design is outstanding. Rugged, stable and with an ad­vanced toroidal airf low design that provides close thermal cou­pling of oven and column. Without sacrificing column accessibility.

Precise temperature controls (directly calibrated from —75° to 400°C with 1° settability) ensure exact short-term and long-term reproducibi l i ty. The complete temperature-time cycle, includ­ing resetting, can be performed

automatically using the auto-door option.

Retention time reproducibility is unprecedented; it compares ex­actly with the Model 900's, as do all other main design parameters.

With the Model 990, you buy the features that you want for the work that you do. Additional com­ponents can be added.

If you'd like the full story, write for our Model 990 brochure to Instrument Division, Perkin-Elmer Corporation, 702 Main Avenue, Norwalk, Conn. 06852.

PERKIN-ELMER