DETERMINATION OF PROFILE OF DISTRIBUTION OF DISSOLVED HYDROGEN SULPHIDE IN WATER Russian patent published in 2015 - IPC G01N27/333 

FIELD: instrumentation.

SUBSTANCE: medium is probed by transducer including ion-selective electrode responding to ions of bivalent sulphur and comparison electrode. Obtained current potentials of said ion-selective electrode are transformed relative to comparison electrode potential to output codes. Said transducer is graduated. Obtained magnitudes of output codes and obtained factors c1 and c0 of graduation equation are used to define current magnitudes of dissolved hydrogen sulphide concentration index for determination of current magnitudes C_SVi of dissolved hydrogen sulphide concentration. Note here that said transducer is graduated in buffer solutions with different dissolved hydrogen sulphide concentrations and with equal magnitudes of each of n preset factors Φ_n affecting the dissociation of dissolved hydrogen sulphide. Obtained codes corresponding to concentrations of dissolved hydrogen sulphide in each buffer solutions are used to get factors c1 and c0 of graduated equation. Then, solutions with different presser values Φ_nz of each of n factors of influence Φ_n where n=1,2,…,m, and with one magnitude C_SV dissolved hydrogen sulphide concentration are used. Defined are output codes N_nz corresponding to magnitudes Φ_nz, where the number z is set for every influence factor Φ_n depending on allowable error of transformation. Obtained magnitudes N_nz of output codes are used to define z-th magnitudes F_z(Φ_nz) of influence function F_n(Φ_n) for every influence factor Φ_n by formula F_z(Φ_nz)=(c1N_nz+c0)-pC_sv. Magnitudes of influence function F_z(Φ_nz) and influence factor Φ_nz allow selection of the type of approximation function F_n(Φ_n) along with definition of influence factors for every influence factor Φ_n with application of one of algorithms for calculation of trend line. During probing of said medium current magnitudes Φ_ni of every factor of influence of dissolved hydrogen sulphide dissociation is measured to define current magnitudes C_SVi of dissolved hydrogen sulphide concentration by formula where N_i are current values of transducer output code. Or, additionally, defined is control magnitude C_SVcontr of dissolved hydrogen sulphide concentration at depth whereat C_SVi is at maximum and equals C_SVimax. Method accepted as a valid one, for example, with the help of direct chemical analysis of medium specimens, is used for calculation of correction factor K_c by formula and definition of current magnitudes C_SVi of dissolved hydrogen sulphide concentration with due allowance for correction in compliance with the formula

EFFECT: decreased measurement corrections and higher degree of automation without in-process graduation of the device.

1 cl, 3 dwg