22A
ANALYTICAL
•wherel
CHEMISTRY
measurements
use the A>Counting-Rate Meter! The Counting-Rate Meter indicates rate of radiation directly; it will show up small variations in rate, and when used with an accessary recorder provides a permanent record. This instrument has a broad field of application. The G-R Counting-Rate Meter is a completely self-contained, a-c instrument for detecting and counting bursts of energy and particles emitted from the nuclei of radioactive materials. The rate of random radiation is indicated visually with the aid of a panel meter calibrated in counts per minute, aurally by a loudspeaker and graphically with an accessory 5ma Esterline Angus pen-and-ink recorder. This continuously recording type of radioactivity indicator has a great advantage over the less expensive and more common scaling instruments in that
the former has no "blind" spots. The Counting-Rate Meter gives a running record showing both the past and present history of radioactive emissions — a scaler can only periodically sample emissions. In medical applications where continuous monitoring is often necessary, the Counting-Rate Meter should be used — similarly, in oil-well surveying, spectrometer techniques, radioactivity health studies, thickness measurements and other nuclear applications. In any radioactivity measurement where the rate may change suddenly, the continuously recording Counting-Rate MH-rr is far superior. ^y jf|
RANGE — 5-swilck positions give full-scale meter readings of 200, 600, 2000, 6000 and 20,000 counts per minute — as little as 5 counts per minute is readable on meter scale. C O U N T E R C I R C U I T VOLTAGE — continuously variable from 400 to 2000 volts, and available at rear of inslrument — means are provided for standardizing voltage. R E C O R D E R O U T P U T — panel jack provided for con· necting a 5ma recorder into the meter circuit.
VERSATILE HAND P R O B E — Geiger-Mueller counter tube and pre-amplifier are built into hand probe at end of 6-foot cable — either self-quenched or internally quenched tubes of any design may be used. ACCURACY— ±3%of full scale— unaffectedby line voltage changes.
METER R E S P O N S E —four different degrees of damping provide varying response speeds to suit different conditions,
Type 1500-B Counting-Rate Meter Type 1509-P4 Beta-Gamma-Ray Counter Tube (lor high enerty emitters) Type 15M-P5 Beta-Gamma Ray Counter Tube (tor detecting low energies) Type 1500-P11 Probe Mounting Stand
GR
Admittance
GENERAL RADIO Company 275 Massachusetts Avenue, Cambridge 39, Massachusetts, U. S. A. •JO West Si. NEW YORK 6
920 S. Michigan
Ave. CHICAGO 5
1000 N. Seward
St. LOS ANGELES 3E
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*=10%
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