ANSitron BRiNGS
Automatic External Standardization to Liquid Scintillation Spectrometry a new FIRST.
. . IN AUTOMATIC LIQUID SCINTILLATION SPECTROMETRY
• Counting efficiency independent of sample counting statistics • Effective over widest range of quenching TYPICAL CALIBRATION CURVE
• Simplified instrument settings
Advantages: External standardization, a feature exclusive to the ANSitron, offers significant advantage over both the "internal standard" and "channels ratio" methods for determining quenching in singly or multiple labeled samples. In contrast to internal standardization, no radioactivity need be added to the sample, thus reducing sample manipulation, eliminating pipetting errors, and leaving the sample unaltered for possible future use. Since the activity of the external standard is chosen to ensure good counting statistics in short calibration periods, counting efficiency is determined independent of sample counting statistics. One of the principal disadvantages of the channels ratio method—inaccurate results at low count rates—is thereby overcome. OPERATION: The ANSitron can automatically determine the activity and quenching in up to 200 samples. After each sample count the ANSitron electronically processes accumulated data and prints out sample number, time, and background-corrected count rate for each channel. Count rate data is stored in electronic memory registers. The external standard— a Cs137 point source—automatically moves to the calibration position and quenching is determined by recounting the sample for a one minute period. Stored data is then subtracted from gross calibration data and the remainder, a direct reflection of sample counting efficiency, is printed for later use with a calibration curve for each isotope—furnished with the instrument—from which counting efficiency may be read directly. The standard source is returned to
its initial shielded position and the cycle is automatically repeated for the next sample. ADDITIONAL EXCLUSIVE FEA TURES: All silicon solid state circuitry for maximum reliability; electronic computation; simplified operation through a new approach to liquid scintillation pulse height analysis combining pulse summation with logarithmic spectrum conversion thus providing greatly increased dynamic range; quartz crystal controlled compensation of counting time for instrumental process time; built-in ratemeters for all counting channels ; low activity rejection system based upon statistical principles; and more. Investigate ANSitron Inc. ANS, . . . a new concept in automatic liquid scintillation spectrometry. WALLINGFORD,
CONN.
Circle No. 19 on Readers' Service Card VOL. 36, NO. 9, AUGUST 1964
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