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In this video conductivity analysis explained in just 1 minute.
The reason that the conductivity of water is important is because it can tell you how much dissolved substances, chemicals, and minerals are present in the water. Higher amounts of these impurities will lead to a higher conductivity.
Water Conductivity
Definition and description
Conductivity of a substance is defined as 'the ability or power to conduct or transmit heat, electricity, or sound'. Its units are Siemens per meter [S/m] in SI and millimhos per centimeter [mmho/cm] in U.S. customary units. Its symbol is k or s.

Electrical conductivity (EC)
An electrical current results from the motion of electrically charged particles in response to forces that act on them from an applied electric field. Within most solid materials a current arise from the flow of electrons, which is called electronic conduction. In all conductors, semiconductors, and many insulated materials only electronic conduction exists, and the electrical conductivity is strongly dependant on the number of electrons available to participate to the conduction process. Most metals are extremely good conductors of electricity, because of the large number of free electrons that can be excited in an empty and available energy state.
In water and ionic materials or fluids a net motion of charged ions can occur. This phenomenon produce an electric current and is called ionic conduction.
Water conductivity

Pure water is not a good conductor of electricity. Ordinary distilled water in equilibrium with carbon dioxide of the air has a conductivity of about 10 x 10-6 W-1*m-1 (20 dS/m). Because the electrical current is transported by the ions in solution, the conductivity increases as the concentration of ions increases.
Thus conductivity increases as water dissolved ionic species.

Typical conductivity of waters:
Ultra pure water 5.5 · 10-6 S/m
Drinking water 0.005 – 0.05 S/m
Sea water 5 S/m

What are the different types of purified water?
When most people think of purified water, they think of water that’s been cleaned somehow. However, there are actually several different types of purified water. Let’s briefly examine the differences between each type.


1. Purified water
Purified water has been stripped of all or most of its impurities. Purified water can still have some impurities in it. But, generally speaking, dissolved solids can’t be more than 10 parts per million in order for the liquid to qualify as purified water.

Water can be purified through many different processes, including distillation, carbon filtration, deionization, and reverse osmosis.


2. Distilled water
Distilled water has been boiled in order to have contaminants removed. As water is boiled, it is captured as steam, and minerals and other compounds are left behind. Once the steam is cooled, it reverts to distilled water.


3. Double-distilled water
Double-distilled water has been through the distillation process twice.


4. Ultrapure water
Ultrapure water, like the name suggests, has been purified to an excruciating level. This water is commonly used in industries that have extremely high standards of cleanliness and water purity, including the semiconductor, pharmaceutical, and solar photovoltaic industries. It’s also used extensively in experiments and research labs.


5. Deionized water
Deionized water has been stripped of mineral ions (e.g., sodium, chloride, and calcium). Deionized water is similar to distilled water, except it usually takes a lot less time to create deionized water.

While ions are removed during the process, viruses and bacteria may still persist in deionized water.


How is conductivity measured?
There are a number of different devices on the market that you can use to measure water conductivity, including:

Handheld Testers are meters that can be dropped into water to measure several characteristics, including conductivity, salinity, temperature, and pH levels, among other things.
Portables are water quality measurement meters that are perfect for field research applications. Researchers in the environmental sector use these devices because they are easy to read in outdoor situations.
Benchtop meters can be used to measure conductivity in laboratory settings. They’re generally bigger than portable testers, and they’re capable of getting more precise readings.
Inline meters are installed permanently in certain locations in a production line to measure water quality characteristics, including conductivity, in real time.
Electrodes are used to conduct electrical currents in order to test certain properties of liquids (e.g., how conductive they are).
Now that you’ve learned about what conductivity is, why it’s important in purified water quality testing, and how conductivity is measured, let’s take a look at some industries that need to measure water conductivity.