These important points underscore the importance of actually measuring the molecular hydrogen concentration and making comparisons between hydrogen-water devices based off H 2concentrations, as opposed to pH and ORP alone. ORP Misconceptions Another important point is that once the water is at a pH around 9.5 the ORP meter is virtually an invalid method to compare any solutions H 2concentration. 8Possibly because at these higher pHs the H +ion concentration is very low (1 X 10 -10M) and may be near the the detection limit of an ORP meter resulting in spurious readings. 8MHF has measured some waters with equal pH and ORP, but one has a concentration four times as great as the other one. This can make a significant difference in the therapeutic value of the water. ORP is unaffected by temperature but readings will vary as the pH fluctuates. As the pH goes up, the millivolt reading on an ORP meter will go down. This can greatly affect the effectiveness of sanitizers such as chlorine, which is by far the most commonly used chemical for water sanitation. For example, at a pH 6.0, 96.5% of the Free Available Chlorine in the water is in the active killing form, while at pH 8.5, only 10% is in that form. Bringing the pH down or adding more sanitizer will raise the millivolt reading.

For use when measuring resistivity boiler and cooling water, lakes, wells etc. Recommended standard - 442-3000 The working principle of an ORP meter or redox meter is quite simple. It is a measurement of water’s capacity for electron transfer. The ORP meter consists of an electrode that is used as a probe or sensor to measure the redox potential of water. The working is similar to pH measurement. Just like the pH of a solution is measured based on hydrogen ion activity, the ORP measurement is a result of electrons’ movement inside the water. Depending on the quality of water, the Automatic or manual temperature compensation - pH sensors incorporate a built-in temperature sensor. Designed for universal applications, HI-98190 measures pH/ORP and temperature. Exchange out the pH probe for an ORP probe to obtain mV readings in the ±2000 mV range.You can make the ORP negative by decreasing the H +concentration (raising the pH) and/or increasing the dissolved molecular hydrogen concentration. Conversely, you can make the ORP positive by increasing the H +concentration (lowering the pH) and/or decreasing the dissolved molecular hydrogen concentration. Important Considerations Because of the close relationship between pH and ORP, there is a scale that takes into account the ratio (mV) ORP/pH, the rH scale. The rH range varies from 0 to 42, where the extreme values represent the reducing effect of an atmosphere of pure hydrogen (rH=0) and to the oxidizing effect of an atmosphere of pure oxygen (rH=42), respectively.

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. Now that it discussed where and when one can use the ORP meters, then let us take forward to how ORP Meter works.

Advantages of METTLER TOLEDO’s ORP Meters

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. ORP readings are measured in mV and range from -2000 mV to 2000 mV. Values above zero indicate an oxidizing substance while values below zero indicate a reducing substance. Values do not indicate the concentration but rather the potential of the substance to oxidize or reduce.

SHIRAHATA, S. A. N. E. T. A. K. A. (2002). Reduced water for prevention of diseases. Animal Cell Technology: Basic and Applied Aspects 12, 25-30. User adjustable temperature compensation (up to 9.99%/°C) which also allows TC to be disabled for applications requiring non-compensated readings. Miyashita, Kazuo, et al. (2003) “Antioxidant Activity of Electrolized Sodium Chloride.” Book Food Factors in Health Promotion and Disease Prevention. P. 274-288. American Chemical Society Symposium Series, V. 851Accuracy of pH measurements is dependent upon well maintained and properly calibrated instruments. The main factors that degrade the performance of an electrode are coating, contamination and aging. Necessary maintenance and calibration depends on these factors and, of course, of the accuracy required from measurements. Therefore, the answer to when to use ORP meters becomes a little complex. Although, a simplified answer to this question can be to use when the water is being treated or processed. The following are a few examples of applications where ORP meters can be used to identify water quality. ORP measurement is important for many applications such as drinking water, swimming pools and spas maintenance, cooling tower disinfection, groundwater remediation, bleaching, cyanide destruction, chrome reductions, metal etching, fruit and vegetable disinfection and de-chlorination. ORP is also the only practical method we have to electronically monitor sanitizer effectiveness. This is an important part to consider regarding the molecular hydrogen concentration. Because the pH plays such a large role in the ORP, you can have one glass of ionized water with an ORP of -800 mV and another with an ORP of -400 mV, but (because of pH differences) the second glass can actually have more therapeutic molecular hydrogen than the first glass. Remember, a negative ORP is more of an indicator of the presence of H 2gas than a measure of concentration. Indeed, it’s not a measurement of concentration at all. Free chlorine is not measured directly, rather calculated using ORP, pH and temperature measurements. Frequency - Every 2 weeks (pH).

As with pH meters, regularly cleaning and properly storing ORP electrodes is important in ensuring accurate results. ORP meter, however, do not require calibration. 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?The platinum sensor is often preferred because it is mechanically simpler and safer to produce. Platinum can be welded to glass and has the same thermal coefficient. Sensors made of gold cannot be welded to the glass and are often placed in plastic supports applied to the glass or plastic tube by means of tiny elastomeric bungs. The gold or platinum sensor signal is carried through the electrode body, and together with the reference signal is conducted to the measurement meter via a coaxial cable with BNC connector. Another common misconception is trying to relate ORP to cellular voltage. 14Some have claimed that because cells have a negative voltage, drinking negative ORP water is healthy. 14However, these two voltages are very distinct from each other and do not relate under biological conditions. Cells have their voltage due to differences in ion gradients and carboxylate moieties from proteins and fatty acids. 15 all types of water testing. The factors like pH level have a high impact on the ORP readings. If the pH of water is higher than 9.5, then ORP meters become an invalid method of water quality measurement. OSTOJI?, S. M., STOJANOVI?, M. D., CALLEJA-GONZALEZ, J., OBRENOVI?, M. D., VELJOVI?, D., ME?EDOVI?, B., KANOSTREVAC, K., STOJANOVI?, M. & VUKOMANOVI?, B. (2011). Drinks with alkaline negative oxidative reduction potential improve exercise performance in physically active men and women: Double-blind, randomized, placebo-controlled, cross-over trial of efficacy and safety. Serbian journal of sports sciences 5, 83-89. Alternatively, a consultation visit from one of our highly experienced product specialists is available for this range. Typically our specialist will be able to go through the following aspects with you to help you make the right choices and be able to deliver them on time and and on budget.