Patent ID: 11959870
Assignee: HACH COMPANY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 19:
20. A method for measuring the pH of a sample, comprising:
introducing a sample to a sample region of a measurement device;
the measurement device comprising:
a pH measurement electrode and a ground electrode contacting the sample;
a low-slope reference electrode, in a reference electrode assembly, having a sensitivity to an analyte of less than about 55 mV/decade, wherein the electrolyte solution is in contact with the low-slope reference electrode, wherein the electrolyte solution is electrically coupled to the sample via at least one salt bridge, wherein the low-slope reference electrode comprises an ion selective electrode for a particular ion in a solution comprising the particular ion;

measuring a first potential between the pH measurement electrode and the ground electrode;
measuring a second potential between the low-slope reference electrode and the ground electrode; and
determining a pH based on hydrogen ion concentration in the sample by comparing the first potential and the second potential.