| 摘要 |
PURPOSE:To enable speedy and accurate detection of concentration of hydrofluoric acid, by measuring and operating the voltage proportional to densities of two kinds of standard liquid subjected to measurement in ppm of the hydrofluoric acid and the sample. CONSTITUTION:A memory unit M stores densities of hydrofluoric acid CA, CB of two standard liquids in ppm which have the same composition and concentration as a surface treatment liquid of aluminum food-stuff can, but with a different kinds of hydrofluoric acid. A controlling unit C supplies alternatedly and in due order samples of the standard liquid, treatment liquid to a measuring tank. A detecting unit is incorporated in the measuring tank and delivers voltages EA, EB, EX expressing hydrofluoric acid concentration of each liquid of the standard liquid and the sample. An operating unit A operates the hydrofluoric acid concentration CX of the sample from voltages EA, EB, EX obtained by the detecting unit and CA, CB stored in the unit M and a display unit displays the concentration CX in ppm through calculation. |
