Digital ORP meter


The ORP meter measures the oxidation potential (Oxidation/Reduction/Potential) of the water, the electrical charge (in millivolts). It is a very sensitive digital device and is used both to measure alkaline water, whose value will be negative from -200 mV. Like acidic water, whose value will be positive from +100 mV.

SKU: J10034 Category:


The redox potential (ORP), also called redox potential (from the English RedOx – Reduction / Oxidation), characterizes the degree of activity of electrons in redox reactions, that is, reactions associated with the addition or transfer of electrons.

The value of the redox potential for each redox reaction is calculated using a fairly complex formula, expressed in millivolts, and can have both positive and negative values. In natural water, the value of Eh varies from – 400 to + 700 mV, which is determined by the entire set of oxidative and reduction processes that occur in it. About equilibrium conditions, the ORP’s value can to some degree describe it’s current liquid enviroment, and its value allows us to get some general conclusions about the water’s chemical composition. Depending on the ORP value, there are several main situations that occur in natural waters:


It is characterized by the values ​​of Еh > + (100 – 150) mV, the presence of free oxygen in water (an oximeter is used for measurement), as well as a number of elements in the highest form of their valence. (Fe3 +, Mo6 +, As5-, V5 +, U6 +, Sr4 +, Cu2 +, Pb2 +). The most common situation in surface waters.

Transient redox:

It is determined by Еh values from 0 to + 100 mV, unstable geochemical regime and variable content of hydrogen sulfide and oxygen. Under these conditions, both weak oxidation and weak reduction of various metals take place.


It is characterized by Еh < values 0. It is typical for groundwater, where low valence metals (Fe2+, Mn2+, Mo4+, V4+, U4+) are present, as well as hydrogen sulfide.

The redox potential is temperature dependent and correlates with pH. In some applications (eg swimming pool water treatment) ORP is one of the main parameters for water quality control. In particular, because it allows you to assess the effectiveness of water disinfection.

Range from 0 to +/- 1999mV

Resolution 1mV

Includes 4 1.5V batteries (AG-13)


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