JULY
1947
27A
1U New. BECKMAN MODEL H E pH METER
POLAROGRAPH SARGENT-HEYROVSKY MODEL XII
The First Portable A C pH Meter with DC Accuracy, Simplicity and Dependability
IMMEDIATE DELIVERY !
Operates Directly from 115 v o l t 50-60 c y c l e Lines — Completely Self-contained The new Beckman Model H pH Meter represents an achievement in the field of pH measurements. Designed to meet the demand for a portable AC operated pH meter, it is completely self-contained, simple to operate, accurate to 0.02 pH units with careful technique and capable of utilizing the variety of standard Beckman electrodes. It is an instrument embodying advancements in circuit design that assure high operating efficiency and dependability. Full AC Operation: Direct operation from 100/130 volt, 50/60 cycle AC lines. Power consumption only 35 watts. H i g h A c c u r a c y : Equivalent to battery operated pH meters. For rapid work accuracy of 0.1 pH is easily obtained. Careful technique permits readings to 0.02 pH units. Standardization: One buffer and one electrical adjustment standardize instrument. Built-in T e m p e r a t u r e C o m p e n s a t i o n , 0 to 100 C: Automatic compensation for effect of temperature changes on the EMF of glass electrode over entire range of instrument. pH a n d Millivolt S c a l e s : Dial reads 0.0 to 7.0 pH, 7.0 to 14.0 pH, 0.0 to 410 mv. Range switch permits measurement on selected scale. No. 6875—Beckman Model H Portable AC pH Meter — Complete with 5" Glass and Calomel Electrodes, Electrode Holder, Holder Rod, 50 ml. Pyrex Beaker, one pint concentrated Buffer Solution pH 7.00, 100 ml. KC1 Solution, 5 foot extension cord with fused plug. For 100/130.».* _ · _ _ volt 50'60 cycle AC opération J | KO.00
THE CHEMICAL RUBBER CO. Scientific Equipment, Analytical Chemicals, Laboratory Supplies HANDBOOK OF CHEMISTRY AND PHYSICS
231U Superior Ave.
Cleveland 14, Ohio
Visual deflection and photographic recording for c u r r e n t permits operator to see actual image of galvanometer d e flection on translucent scale as it is being recorded — 150 mm current axis—current sensitivity 4 χ 10"9 ampere per millimeter (allowing analysis of solutions as dilute as 10"6 normal) — sensitivity control is supplied by panel mounted precision Ayrton shunt with ratios from l ' l to 1-Ί00Ο—output circuit is equipped with optional Hoekstra shunt connection which provides for plus or minus polar ization of the cathode to be. represented by voltage axis of single uni-directional record—provision for instant manual adjustment of record position and applied voltage—actual applied voltage readily determinable at all times by multi plying volt meter reading by indicated graduations on camera scale r i n g - r e c o r d i n g system is driven by constant speed motor—all scales and windows are actinic filters and the camera is a "light tight" unit that may be removed from the instrument outside the dark room. MULTI-CURVE RECORDING ,, p o s i t i o n s c a l e r i n g of camera cylinder permits adjustment of the starting posi tion so that numerous curves can be plotted on a single recording sheet without removing it from the instrument.
SIMPLE DEVELOPING PROCEDURE-low sensitive bromide paper 6" χ 10" is used in the camera—no need to meet time temperature and light requirements of ordinary photographic development—no film is used—no printing to be done—minimum d a r k room requirements. LIGHT W E I G H T - S M A L L SPACE R E Q U I R E M E N T Model XII Polarograph weighs approximately 65 lbs. net — the dimensions are 13V4" x 13V2" x 12 1 /;", requiring only very small space in the laboratory. 5 - 2 9 3 0 1 —Polarograph, Heyrovsky, American model XII Indicating-recording, complete with 3 vessels S-29305 30 m m ; 1 electrode S-29340. 21 cm capillary tubing, S-29350 3 stoppers for vessels, 4 packages bromide paper S-29347 3 feet neoprene tubing 3/16 inch, m e r c u r y reservoir 125 ml S-44345 and connecting wires. For operation from 115 volt A.C. 60 cycle circuit $550.00
SARGENT SCIENTIFIC LABORATORY EQUIPMENT AND CHEMICALS E. H. SARGENT & C O M P A N Y , 155-165 EAST SUPERIOR ST. · CHICAGO 11.ILL· M I C H I G A N D I V I S I O N 1959 EAST JEFFERSON • DETROIT.
MICHIGAN
