be suppressed. A new version of such a controller, known as a phototransistorized proportional con troller, has been placed on the mar ket. It operates on the principle of a light beam being interrupted when a set point is reached. This controller is adaptable to regula tion of temperature as well as other functions. Proportional action of the NIEAF controller is based on the system of switching modula tion. Prices on request. Dept. IEC, Commercial Div., Netherland Consulate General, 10 Rocke feller Plaza, New York 20, Ν. Υ.
306
Why waste time t h u m b i n g through old bulletins and back-issue periodi cals f o r p r o c e s s i n g i n f o r m a t i o n ? CHEMICAL ENGINEERING CATALOG will get you all the right answers quickly and accurately! CEC's five-way index contains a com pany catalog list, functional guide, equipment and materials of construc tion section, engineering services sec tion, and trade names index. It will take you to just the data you need.
Use CHEMICAL ENGINEERING CATALOG often . .. it's published for process men, by process men, to serve you.
CHEMICAL ENGINEERING CATALOG Rotameter
Transmitters
Solid state electric rotameter transmitters which operate on an induction principle have been an nounced. Units are capable of measuring and transmitting flow rates up to 200 gallons per minute in pipelines up to 3 inches at pres-
REINHOLD PUBLISHING CORPORATION 4 3 0 Park Avenue, New York 2 2 , Ν. Υ. Circle No. 47 on Readers' Service Card
How to get drier or cooler AIR or GASES at low cost N I A G A R A AERO® AFTER COOLER
c o o l s a compressed gas, or air, below t h e temperature of the surrounding a t m o s p h e r e , t h u s p r e v e n t i n g the c o n d e n s a t i o n of moisture in your lines. T h e gas will contain only half o f t h e moisture left in it by conven t i o n a l methods. Even drier gas can b e p r o d u c e d if you require it. In working -with controlled at mospheres of inert gases to prevent undesired reactions, this dryness of the gas at low cost is a great ad vantage. The cost of the Niagara method is low because it uses evap orative cooling, saving 9 5 % of the cost of cooling water (and its pip ing and pumping). This direct sav ing of cost pays for the N i a g a r a cooler in less than t w o years.
If you use compressed air to operate instruments or pneumatic equipment you will get better re sults by using the Niagara Aero After Cooler. W r i t e for Bulletin 130, or ask nearest Niagara Engineer if you have a problem involving the in dustrial use of air.
N I A G A R A BLOWER C O M P A N Y (Continued
on page 86 A)
Dept. EC-12, 4 0 5 Lexington A v e . , N e w York 1 7 , N . Y . Niagara District Engineers in Principal Cities of U. S. and Canada Circle No. 30 on Readers' Service Card
VOL. 53, NO. 12 ·
DECEMBER 1961
85 A
