VOLUME
20, NO. 6, J U N E
19 A
1948
SARGENT POLAROGRAPH MODEL XXI IMPROVED REDESIGNED The Sargent Polarograph, Model XXI, Represents the Latest Development in Polarographlc Instrumentation This potentiometric, visible-recording instrument is the successor to the well-known Model X X and embodies several new features of construction and design. A twenty-step integrally variable sensitivity control assures more positive sensitivity reproduction. An R. C. filter type damping control, for placing a capacitance in parallel with the measuring resistor at high sensitivity settings and an additional series resistor and parallel capacitance at low settings, has been substituted for the straight capacitance type. A new switch arrangement permits initial potential to be applied either in the same direction as the span potential or counter to it. The bridge has been completely enclosed, heavier wire used throughout and the unitized
panel construction of the Polarograph circuit permits it to be removed from the instrument case, in one piece, for servicing. The instrument is slightly smaller than the former Model X X and has the following characteristics: Current Sensitivity Range .003—1.500 microamperes per mm. Inherent limit of Instrumental accuracy 0.5% of the current measured. Time of full scale traverse, 10 seconds. Time of rotation of bridge, 131/^j minutes. Power consumption, 100 watts. S-29303 POLAROGRAPH—MODEL X X I , Visible Chart Recording, Sargent. Complete with accessories. For operation from 115 volt 50/60 cycle circuits $1650.00
SARGENT SCIENTIFIC LABORATORY EQUIPMENT AND
CHEMICALS
E. H. SARGENT & COMPANY, 155-165 EAST SUPERIOR ST. CHICAGO11, ILL. M I C H I G A N DIVISION 1959 EAST JEFFERSON DETROIT MICHIGAN
