Beckman® INSTRUMENTS, INC. - Analytical Chemistry (ACS

---

Model RC-16B2 1 % Accuracy

Model RC-18A Accurate to ± 0.05% Laboratory Conductivity Cells

FOR ACCURATE MEASUREMENTS OF SOLUTION CONDUCTIVITY RC-18A CONDUCTIVITY BRIDGE - Provides compactly and economically in one housing, an oscillator that provides both 1,000 and 3,000 Hz bridge current, decade and ratio resistors that comprise the bridge, decade and continuously variable capacitors that facilitate reactive balance, a modified Wagner ground balance, a sharply tuned high-gain amplifier, and a 2" CRT null detector. Accuracy of the bridge is ±0.05% of the reading above 300 ohms while below this value it is limited by the resolution of the last decade dial. Sensitivity exceeds 0.005%. The overall instrument range is 0-111,111 ohms in steps of 0.1 ohms and 0-11,111 micromhos in steps of 0.01 micromho. RC-16B2 CONDUCTIVITY BRIDGE - L i n e operated, compact, general purpose laboratory instrument with uniform 1% accuracy over the whole range of the instrument and sensitivity at least three times better. Extremely wide range: 0.2 to 2,500,000 ohms and 0.4 to 5,000,000 micromhos. True AC Wheatstone Bridge measuring circuit requires no adjustments to readout in absolute ohms. "Eye" tube null indicator

Beckman'

for clear indication of electrode polarization. When used with conductivity cells of appropriate cell constants, the entire range of electrolytic conductivity from that of ultra-pure demineralized water to concentrated strong acids is easily covered. LABORATORY CONDUCTIVITY CELLS -Choose from a complete range of pyrex glass dip cells with cell constants within ± 1% of nominal value for use with the RC-16B2. Jones type cells with cell holders and constant temperature bath available for use with the RC-18A.

ELECTROLYTIC CONDUCTIVITY IS OUR BUSINESS and we'd like to tell you about our other bridges, cells and accessories designed exclusively for laboratory solution conductivity measurements. A set of three highly informative pamphlets are available just for the asking. Write today to

I N S T R U M E N T S , INC. CEDAR GROVE OPERATIONS 89 COMMERCE ROAD CEDAR GROVE, NEW JERSEY · 07009

INTERNATIONAL SUBSIDIARIES: Geneva; Munich; Glenrothes, Scotland; Tokyo; Paris; Capetown; London; Mexico City. Circle No. 9 on Readers' Service Card

122 A ·

ANALYTICAL CHEMISTRY

See ACS Laboratory Guide for All Products/Sales Office