What is pH Meter and How does it Work?


As a scientist, student, or even a concerned mother, you may have often wondered about the nature of the water you are consuming and think whether the water is safe or not. This fretting can be eliminated with the use of a pH meter whose versatility is unbound.

how does a ph meter work

A pH meter can accurately measure the concentration of hydrogen ions in any solution and facilitate scientific or personal observations.

Not only does it help the genius scientists in their ominous lab while doing some experiment, but they are employed in a variety of fields such as agriculture, industries, school-work, or even just household.

Due to this wide application, they have emerged as an essential commodity to own. It is equally essential to have a brief knowledge about its functionality and operation to draw accurate results from your experiment.

Before that, let’s do a quick introduction of what a pH meter does.

What is pH Meter?

A pH meter is an instrument used to measure the concentration of hydrogen ions in a given solution. The acronym pH has been deciphered in many ways, most commonly as “power of hydrogen” and “potential of hydrogen. It indicates the precise number of hydrogen ions present in a definite quantity of liquid.

what is ph meter

A pH meter can also measure the voltage produced by certain solutions, which further tells whether the solution can produce an electric current or not.

Acidic solutions have more positively charged hydrogen ions, while alkaline solutions have more negatively charged hydrogen ions. The acidic solution, thus, has the potential to produce an electric current.

You might think that a device with such a baffling explanation could not be of any use to you. Regardless of its literal chemical definition, pH meters have a variety of uses apart from being essential in chemical laboratories.

They can be employed in an agricultural field to assess water quality for the crops and municipal water supplies. It is also used to determine the hydrogen-activity in swimming pools, wine, and beer brewery.

How does a pH Meter Work?

Before getting into the pH meter's working process, buy the best pH meter from our recommended list for hands-on training.

  • A pH meter consists of the meter body and a moving-coil meter or the digital meter and a probe immersed in the solution you intend to observe. 
  • The probes are generally made of glass and are highly prone to damage. Thus, it is essential to make sure that the probe is not broken before starting your experiment, or you may get faulty results.
  • The glass electrode consists of potassium chloride, which is a neutral solution with a pH of 7. It contains a definite amount of hydrogen ions.
  • We’ll consider this solution as the benchmark and make the ensuing observation, keeping that in mind. Now let’s imagine that the solution being tested is acidic; it then contains more hydrogen ions.
  • The pH meter will measure the difference between the solution in the glass electrode and the acidic solution by measuring the difference between the voltages produced by hydrogen-ions of each of the solutions.
  • We already know the pH value of the neutral solution is 7. By keeping this in mind, we can determine the pH of the test sample.
  • Now, to assess the electric potential of a solution, you have to immerse the tipping probe completely into the solution. The results will be displayed on the moving coil-meter or digital meter.
  • The moving coil meter consists of a pointer that moves up and down against the scale fitted. Although digital meters are more in demand than a moving-coil meter, the latter can be more accurate than the former sometimes.
  • Once you have assessed the electric potential of the solution under observation, you can go ahead and test the authenticity. To test this, you have to make a complete circuit to ensure whether the electricity flows through the solution or not. 


pH meter is of utmost use for an array of reasons, which has been made pretty evident. You can also use the pH meter to test the nature of the water you are drinking and know if it has just the right concentration of hydrogen ions.

If used smartly, it can prove to be highly useful and effective. It may take time to get used to the operation, but once you get its hang, you will realize just how reliable it is.

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About the Author


I am Tim, a weather enthusiast who loves to watch hurricanes and all other harsh weather conditions. I studied B.Sc(Meteorology) at the University of Miami. With excellent knowledge of Weather Forecasting, Meteorology, and Environmental Science, I am currently working in San Francisco as a Meteorologist. Also, I am a member of The Weather Channel and AccuWeather. In this blog, I will write a detailed review of Weather instruments that you need for survival and other activities.