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Potentiometry passively measures the potential of a solution between two electrodes, affecting the solution very little in the process. One electrode is called the reference electrode and has a constant potential, while the other one is an indicator electrode whose potential changes with the sample's composition.
A potentiometer being calibrated and then measuring an unknown voltage. R 1 is the resistance of the entire resistance wire. The arrow head represents the moving wiper.. In this circuit, the ends of a uniform resistance wire R 1 are connected to a regulated DC supply V S for use as a voltage divider.
The word rheostat was coined in 1843 by Sir Charles Wheatstone, [7] from the Greek ῥέος rheos meaning "stream", and - στάτης-states (from ἱστάναι histanai, "to set, to cause to stand") meaning "setter, regulating device", [8] [9] [10] which is a two-terminal variable resistor. For low-power applications (less than about 1 ...
In analytical chemistry, potentiometric titration is a technique similar to direct titration of a redox reaction. It is a useful means of characterizing an acid. No indicator is used; instead the electric potential is measured across the analyte, typically an electrolyte solution.
Standard hydrogen electrode scheme: 1) Platinized platinum electrode, 2) Hydrogen gas, 3) Acid solution with an activity of H + = 1 mol/L, 4) Hydroseal for prevention of oxygen interference,
The most common types of reference electrodes used in analytical chemistry include the standard hydrogen electrode, the saturated calomel electrode, and the Ag/AgCl electrode. [3] The standard hydrogen electrode (SHE) is the primary reference electrode that has a potential of 0 volts at all temperatures and a pressure of 1 atm.
Potentiometric solid state gas sensors have been generally classified into three broad groups.. Type I sensors have an electrolyte containing mobile ions of the chemical species in the gas phase that it is monitoring.
Beckman Model M pH Meter, 1937 [1] Beckman model 72 pH meter, 1960 781 pH/Ion Meter pH meter by Metrohm. A pH meter is a scientific instrument that measures the hydrogen-ion activity in water-based solutions, indicating its acidity or alkalinity expressed as pH. [2]