ANALYSIS OF MANUFACTURING PROCESS OF ASBESTOS CEMENT BOARD BY GAMMA-RAY CONCENTRATION METER AND BETA-RAY THICKNESS-GAUGE

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Proc. Japan Conf. Radioisotopes

OSTI ID:4708110

Imamura, H; Uchida, K; Tominaga, H

For the purpose of getting data for process control, two gamma sources (Cs/sup 137/ 1C and 0.5C) were set outside of two vats of the wet machine and G-M probes were put into both vats, then concentrations of the slurries (about 15% in weight, 1.11 in specific gravity) were observed continuously by detecting transmitted gamma rays. By gaging levels of the slurries in both vats with the usual air-purge method, weight thickness of raw slate (about 0.6 g/cm/sup 2/) were measured by beta transmission (Sr/sup 90/ 100mC). The distance of gamma transmission in the slurry was set at 40 to 50 cm, in order to keep precision within plus or minus 0.5% in concentration or plus or minus 0.004 in specific gravity. In the beta transmission gage, the mass absorption coefficient determined was 8.9 cm/sup 2//g in the thickness range 0.6 to 0.7 g/cm/sup 2/; consequently precision in thickness was about 2 mg/cm/sup 2/. From records of both concentrations, both levels, and slate thickness observed over three days, calculations were made of standard deviations, simple correlation coefficients, partial correlation coefficients between thickness and other variables, and regression coefficients of thickness upon other variables with confidence intervals. It was found that in order to control slate thickness within plus or minus 3% (relative), it was necessary to keep the slurry concentration in the range of fluctuation of plus or minus 0.6 per cent (absolute) and the levels in the range of plus or minus 4 cm. It was concluded that the concentration is a more important quantity than the level of slurry as a control factor in the manufacturing process. (P.C.H.)

• Research Organization: Ube Industries, Ltd.
• NSA Number: NSA-17-030172
• OSTI ID: 4708110
• Journal Information: Proc. Japan Conf. Radioisotopes, Journal Name: Proc. Japan Conf. Radioisotopes Vol. Vol: 5th, No. 4
• Country of Publication: Country unknown/Code not available
• Language: Japanese

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