electronic temperature control* IN FISHER ISOTEMP B A T H . . .
provides: EASY TEMPERATURE SETTING
CONSTANCY TO WITHIN 0.005° C WIDE RANGE: — 5° to+ 107° C Photo courtesy o f G u l f Research a n d Development Laboratories. * TEMPERATURE IS CONTROLLED BY A SENSITIVE RESISTANCE THERMOMETER I N A BRIDGE CIRCUIT, THE OUTPUT O F W H I C H IS AMPLIFIED M A N Y TIMES O V E R A N D M A D E T O OPERATE A N ENCLOSED MERCURY RELAY. RESULT: STABLE, CHATTER-FREE O P E R A T I O N A N D Q U I C K , EASY SETTING.
W i t h i n t h e new Fisher Isotemp Bath t h e counter thrust impellers (1 a n d 2), sensitive control element (3} a n d h e a t e r coils ( 4 ) — a r e a l l contained in central housing (5) t o p r o v i d e a m p l e w o r k i n g space a n d f r e e access t o the Bath.
The Fisher Isotemp Bath has wide range, great sensitivity and simple, speedy manipulation. Because the bath's temperature is electronically controlled, there is a variation in the entire 10-gallon bath of less than five thousandths of a degree Centigrade. Thus, the Fisher Isotemp Bath outperforms even the sensitive differential thermometers which were used to test and perfect it. It offers a temperature range of 112 degrees: from —5° to -|-107 o C. and the temperatures are reproducible: re-setting to any desired temperature is simply a matter of turning dials. The action of the stirrers creates a rapid flow of liquid across the heaters and regulator in the housing, assuring a complete circulation of the bath's entire contents (ten gallons) many times a minute. Because the bearings and sealing mechanism are graphite and stainless steel, with adjoining surfaces finished to match within several wave lengths of light, operation is equally satisfactory under such diverse conditions as those offered by water, paraffin oil, mineral oil and dioctyl phthalate. The bath itself is made of Pyrex Brand Glass, 15 in. in diameter and 15 in. high. Entire top of bath is open and unobstructed. Write to 717 Forbes Street, Pittsburgh, Pa., for illustrated booklet FS-211-C which completely describes Fisher Isotemp Bath
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America's Largest Manufacturer-Distributor of Laboratory Appliances and Reagent Chemicals For further information, circle number 30 A on Readers' Service Card, page 39 A
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