| 摘要 |
<p>1,167,199. Electro-chemical analysis. GALGON CORP. Sept. 27, 1967 [Oct.17, 19661. No. 44082/67. Heading G1N. [Also in Division G3] A method for quantative analysis of a known constituent ionized in solution comprises measuring the conductivity of the solution, adding excess buffering agent reacting with the constituent and again measuring the conductivity. The amount of the constituent is then determined from a curve of differential conductivity versus concentration, previously prepared from measurements with known concentrations. In an industrial process the differential conductivity signal may be used for controlling the addition of the constituent to the solution. Several examples are given of determining:- (i) alkalinity of boiler feedwater or effluent from lime-soda water softeners or the concentration of alkali in a sulphate digester for paper processing by neutralizing with CO 2 or (ii) the concentration of sulphuric acid when neutralized by excess ammonia, hydrazine, cyclohexylanine or morpholine. Fig. 1 (not shown) illustrates the application to automatic control of the addition of sodium hydroxide to boiler feedwater. Samples of the boiler water have their conductivity measured in cells (6), (12) before and after CO 2 is introduced in neutralizing chamber (8). The cells are connected in bridge circuits and the output signals connected to a "computor" controlling the hydroxide feed.</p> |
