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Analytical Design of FET-Based Biosensors
Published in Suman Lata Tripathi, Sobhit Saxena, Sushanta Kumar Mohapatra, Advanced VLSI Design and Testability Issues, 2020
Khuraijam Nelson Singh, Pranab Kishore Dutta
They are usually made up of three main components [6]: Working electrode: It is an electrode in which the electrochemical reaction takes place.Reference electrode: It is a stable electrode which potential is used as a reference for potential measurement.Auxiliary electrode: It is an electrode that is used for completion of the circuit of the electrochemical cell.
Analytical Measurements
Published in Douglas O. J. deSá, Instrumentation Fundamentals for Process Control, 2019
Common reference electrodes are of a metal/metal salt solution type, either the calomel (mercury/mercurous chloride) electrode, or the silver/silver chloride electrode that is used as the internal reference electrode in glass electrodes.
External Corrosion Protection
Published in Mavis Sika Okyere, Corrosion Protection for the Oil and Gas Industry, 2019
Reference electrodes are used to measure the oxidizing or reducing power of the working electrode/anode in a cathodic protection system. Cathodic protection reference electrodes are used in locations where a constant, stable reference is required, with constant potential rectifiers and at inaccessible locations. Examples of reference electrodes are Cu/CuSO4 reference electrode and Ag/AgCl reference electrode. The requirements for reference electrodes include small polarization, stability, and long service life.
Improving corrosion resistance of reinforcement steel rebars exposed to sulphate attack by the use of electroless nickel coatings
Published in European Journal of Environmental and Civil Engineering, 2022
Arkadeb Mukhopadhyay, Sarmila Sahoo
The corrosion behaviour of the uncoated and coated rebars was investigated using a standard three-electrode electrochemical cell and potentiostat (Gill AC, ACM Instruments). The uncoated and coated rebar specimens acted as the working electrode (WE). The other two electrodes were saturated calomel reference electrode (RE) and platinum rod (auxiliary electrode (AE). The exposed area of the specimens was 1 cm2 in the electrolyte. The accelerated corrosion behaviour of the rebars to attack of sulphate species was investigated using PDP and EIS tests in 0.5 M H2SO4. While carrying out PDP tests, the WE was polarized in cathodic and anodic directions at 1 mV/s in the range of ±250 mV versus open circuit potential (OCP). An initial settling time of 15 min was allotted for the stabilization of OCP. To carry out EIS, the applied frequency was varied from 10 kHz to 0.01 Hz. The mathematical analysis, Tafel fitting Nyquist plots and adjustment of equivalent electrical circuit was performed with ACM Analysis software. Post corrosion tests, the corroded surfaces were investigated using Field Emission Scanning Electron Microscope (FESEM) (Sigma-300, ZEISS) and EDS.
Smart water management system for residential buildings in Saudi Arabia
Published in Journal of Applied Water Engineering and Research, 2022
Potential of Hydrogen (pH) is a numeric scale applied to indicate the basicity or acidity of an aqueous solution. pH measurement is important in water purification monitoring, which is performed using pH meters. The pH meter has a glass proton-sensitive electrode, which creates a potential corresponding to the pH of a solution with reference to a silver chloride or calomel electrode. The purpose of the reference electrode is to preserve a constant potential at any given temperature. The glass electrode, usually located at the tip of the pH probe, allows hydrogen ions in the solution being measured to diffuse into the outer layer of the glass, whereas larger ions remain in the solution. The hydrogen ions concentration difference between the outside and inside of the probe generates a very small current. Hence, this current is proportional to the concentration of hydrogen ions in the solution being measured with a potential, E, that can be written as where E0 is the standard electrode potential at hydrogen ion activity (aH+) = 1 mol/l, R is the gas constant, T is the temperature in Kelvin and F is the Faraday constant. Most pH sensors are designed to produce an output of 0 mV at 7.0 pH, with a slope, or sensitivity, of −59.16 mV/pH at 25 °C. The ideal pH level of drinking water varies between 6 and 8.5.
An overview of cathodic protection criteria for steel in atmospherically exposed concrete
Published in Corrosion Engineering, Science and Technology, 2020
The most widely used reference electrode for general hand held applications in the field, such as pipeline surveys, is the copper/saturated copper sulphate electrode (CSE). This uses a liquid electrolyte and is unsuitable for embedding in concrete. It also requires great care when used on vertical or soffit surfaces due to the risk of an air gap forming in the half cell. However, many of the potential criteria are referenced to the CSE electrode as it is widely used as a portable electrode for CP systems for pipelines and other buried and submerged steel structures. BS EN ISO 12696 does not recommend the use of CSE electrodes for steel in concrete [2].