The ORP electrodes are designed to 0mV reading that is null reading at 7pH. As the pH value deflects over or below 7, the deflection in ORP is seen. The extreme range of ORP meter reading remains between -1500mV to1500mV. Measuring electrodes are made of platinum or gold, which due to their low resistance, will lose electrons to an oxidant or accept electrons from a reductant. Voltage is produced as electrons are added or subtracted. The reference electrode, usually made of silver, is surrounded by an electrolyte solution that produces another tiny voltage. But the voltage produced by the reference electrode is constant and stable, so it forms a reference against which the voltage generated by the measuring electrode may be compared. The more oxidizer or reductant available, the greater the voltage difference between the solutions. Cannon Water Technology, Inc. being water technology specialists, the company offers a wide range of ORP Meters from several brands like Sensorex, HM Digital, Myron L etc. In addition to being used to monitor water quality in chlorinated pools, ORP meters are widely used in the food processing and water treatment industries to ensure that water is free of contaminants and safe to recycle or consume. Bottled water or tap water that is contaminant-free will have a positive ORP value.

When an oxidizing and/or reducing agent is dissolved into an aqueous sample, they may react with materials present and produce a voltage, or electromotive force (EMF), that is related to the ratio of oxidized to reduce species in the sample. An electron exchange can develop between this solution and an inert metal sensor immersed in the solution, and the voltage can be measured (when compared to a reference electrode) with a pH/mV meter. This type of measurement is known as redox or ORP. The units of measurement are in mV. Oxidation-reduction potentialcan be measured using a potentiometer (voltmeter) or an ORP meter. 1 Water produced from electrolysis (ionized water), as well as other forms of hydrogen water, exhibit a negative ORP. 2 But what is the meter actually measuring? And how does it work? pH measurements are important in medicine, biology, chemistry, agriculture, forestry, food science, environmental science, oceanography, civil engineering, chemical engineering, nutrition, water treatment & water purification, and many other applications.The electrode itself is comprised of a measuring electrode, a reference electrode, and, often, a temperature sensor. Electrode components are usually combined into one device called a combination pH electrode. The reference electrode is filled with an electrolyte of a known value which reacts with the medium being tested. That reaction is what determines the potential of hydrogen. Since pH is sensitive to temperature fluctuations, a temperature sensor is included so readings can be properly compensated. Temperature compensation can be achieved manually or automatically. Manual temperature compensation is usually achieved by entering the temperature of the fluid being measured into the instruments menu. Automatic temperature compensation requires input from a temperature sensor and constantly sends a compensated pH signal to the display.

pH calibration on the meter is performed at either two or three points. You should calibrate with pH 7 buffer first then followed by either pH 4 and/or pH 10 buffers. The recommended frequency of calibration of pH is every 2 weeks. ORP is the acronym for "Oxidizing-Reduction Potential" which is the activity of oxidizers and reducers in relation to their concentration. Oxidizers are chemicals and chemical compounds that accept electrons from other substances while reducers donate electrons. ORP is especially important when discussing water quality as it's most notable feature is its ability to measure the oxidation of contaminants.Tyler LeBaron. (2013 ) “Changes in Oxidation-Reduction Potential of Aqueous Solutions as a Function of pH and Hydrogen Gas Concentration” The Journal of Kitchen Chemistry 2013. 1. P.12 Measures - pH, ORP, free chlorine and conductivity (and resistivity and TDS) - please see product attachments for full measuring ranges. The fact that molecular hydrogen is the therapeutic ingredient in ionized water eluded scientist for decades. 9It is no wonder that misconceptions of ORP have been promulgated over the years. Some have suggested that the reading is due to free electrons, actual physical charges on water molecules, charged or ionic minerals, 10and virtually everything else except for molecular hydrogen. pH and ORP are important parameters of water quality and a wide range of process applications depend upon the ability to measure and control each. In simplest terms, both pH and ORP represent types of ion activity in liquids—pH measures hydrogen ion activity while ORP represents the potential transfer of electrons between chemicals or chemical compounds. Though measuring very different things, both pH and ORP share a close relationship and are often included together while discussing water quality.