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12. APPENDIX
12.1 Absorption Coefficients
Absorption coefficients are valid for:
• 137-Cs at one-point calibration.
• crystal size 25/25 and 40/35
• frontal irradiation
When using a 50/50 crystal, multiply the values listed below by 0.9. With radial irradia-
tion, these values have to be multiplied by 0.85.
For measurements with Co-60 sources the listed absorption coefficients have to be multi-
plied by 0.6.
The absorption coefficients were calculated for average concentrations. Depending on the
resolution behavior, these values may differ with other concentrations.
Absorption coefficients in cm
2
/g
Unit of measurement
Product
g/cm
3
% conc. Conc. in g/l
Whole milk - .0737 - .00018 - .000017
Skim milk - .0737 - .000027 - .000295
Whey - .0737 - .000294 - .0000254
Sugar solution - .0657 - .00044 - .000021
Hydrochloric acid (HCl) - H
2
O - .0608 - .0003 - .000025
Sulfuric acid (H
2
SO
4
) - H
2
O - .0623 - .0005 - .000036
Nitric acid (HNO
3
) - H
2
O - .0576 - .00036 - .000027
Sodium hydroxide (NaOH) - H
2
O - .0664 - .00069 - .000049
Ethanol (C
2
H
6
O) - H
2
O - .0677 + .00014 + .000018
Propyl alcohol (C
3
H
8
O) - H
2
O - .0673 + .00015 + .0000186
Glycerin (C
3
H
5
(OH
3
) - H
2
O - .0667 - .00017 - .000015