An electrode cleaning and calibration system generally comprises a sensor holder assembly machined from a block of solid acrylic or similar plastic material, which can accommodate a variety of types and sizes of sensors for use in monitoring and measurement of water processing and treatment processes. Examples of sensors suitable for use in the system include pH sensors, dissolved oxygen sensors, chlorine sensors, ozone sensors, total suspended solid sensors, mixed liquor suspended solid sensors, ammonia sensors, monochloramine sensors, and ultraviolent transmittance sensors.

Improved methods of manufacturing highly sensitive and selective electrochemical biosensors are provided. The method may comprise washing the nanowell array electrodes of the biosensors with ferricyanide, preferably potassium ferricyanide. The method may also comprise washing the electrodes of the biosensors with methylene blue (i.e., methylthioninium chloride), either in addition to the ferricyanide and/or H2SO4 washing steps, or without the ferricyanide and/or H.sub.2SO.sub.4 washing steps.

Improved methods of manufacturing highly sensitive and selective electrochemical biosensors are provided. The method may comprise washing the nanowell array electrodes of the biosensors with ferricyanide, preferably potassium ferricyanide. The method may also comprise washing the electrodes of the biosensors with methylene blue (i.e., methylthioninium chloride), either in addition to the ferricyanide and/or H2SO4 washing steps, or without the ferricyanide and/or H.sub.2SO.sub.4 washing steps.

An electrochemical method for analyzing the presence of certain analytes in a fluid in concentrations as low as parts per trillion without use of reagents. This is done by using a combination of filtration, microfluidics, increasing the electrochemical gradient, while reducing double layer capacitance, the Nernst layer and other methodologies discussed below. Such a method can be used to get data on certain pollutants like heavy metals in real time and then through internet of things send the data to the Cloud. Such a methodology would help form a nervous system for the planet, wherein pollutants are monitored in real time.

An electrochemical method for analyzing the presence of certain analytes in a fluid in concentrations as low as parts per trillion without use of reagents. This is done by using a combination of filtration, microfluidics, increasing the electrochemical gradient, while reducing double layer capacitance, the Nernst layer and other methodologies discussed below. Such a method can be used to get data on certain pollutants like heavy metals in real time and then through internet of things send the data to the Cloud. Such a methodology would help form a nervous system for the planet, wherein pollutants are monitored in real time.

This disclosure relates to improved devices, systems and methods for detecting and measuring oxidizing compounds in test fluids. Certain embodiments include a measurement device configured to apply a constant current to the test fluid and measure a reference voltage indicating an electrochemical potential at which electrolysis occurs in the test fluid. The measurement device is further configured to measure a second voltage indicating an oxidizing potential of the test fluid, and to calculate an oxidizer concentration measurement indicating the concentration of the oxidizing compound in the test fluid based on a voltage difference between the reference voltage and the second voltage.

This disclosure relates to improved techniques for detecting and measuring oxidizing compounds in test fluids. Certain embodiments can include a measurement device that can be configured to apply a constant current to the test fluid and measure a reference voltage indicating an electrochemical potential at which electrolysis occurs in the test fluid. The measurement device also can be configured to measure a second voltage indicating an oxidizing potential of the test fluid, and to calculate an oxidizer concentration measurement indicating the concentration of the oxidizing compound in the test fluid based on a voltage difference between the reference voltage and the second voltage.

A method of exposing a sample to an electrical effect for electrochemical analysis of the sample in an electrolyte solution is disclosed. The method comprises causing an external electrical conductor of an electrode head to apply the electrical effect, the external electrical conductor of the electrode head being external to the electrode head and on an external side of the sample exposed to the electrolyte solution. Apparatuses are also disclosed.

Methods and systems for identifying contamination of an electrochemical sensor (10) and cleaning the electrochemical sensor (10) are provided. A method may comprise scanning the sensor (10) for the first time using CV to generate a reference set of readings; scanning the sensor (10) for the second time after the sensor (10) has been employed; comparing a second set of readings from the second CV scan to the reference set of readings; when the second set of readings is different from the reference set of readings, determining that the sensor (10) potential has shifted; scanning the sensor (10) for the third time to clean one or more elements of the sensor (10); scanning the sensor (10) for the fourth time; comparing a fourth set of readings from the fourth CV scan to the second set of readings; and determining that the potential of the sensor (10) has shifted due to pollution of the sensor (10), and/or that the sensor (10) can be further cleaned.

Methods and systems for identifying contamination of an electrochemical sensor (10) and cleaning the electrochemical sensor (10) are provided. A method may comprise scanning the sensor (10) for the first time using CV to generate a reference set of readings; scanning the sensor (10) for the second time after the sensor (10) has been employed; comparing a second set of readings from the second CV scan to the reference set of readings; when the second set of readings is different from the reference set of readings, determining that the sensor (10) potential has shifted; scanning the sensor (10) for the third time to clean one or more elements of the sensor (10); scanning the sensor (10) for the fourth time; comparing a fourth set of readings from the fourth CV scan to the second set of readings; and determining that the potential of the sensor (10) has shifted due to pollution of the sensor (10), and/or that the sensor (10) can be further cleaned.