PH meter, what is it and which one to choose?

November 2, 2021

To talk about a pH meter, you must first be clear about what pH is; this is a concentration of hydrogen that can modify the degree of basicity or acidity of a solution. PH is measured on scales from 0 to 14, with 7 being a neutral term, pH greater than 7 is considered acidic, while pH less than 7 is considered basic or alkaline.

A pH meter, also called a pH meter, is used to calculate these pH levels and obtain the concentration measure of the substances being measured.

How to use the pH meter?

The first thing when using a pH meter is to calibrate or adjust it, for this it is necessary to use a buffer solution . It is not possible to calibrate the meter to a scale greater than 7, although it is recommended for a much higher precision that it be calibrated in 2 different values .

Most pH meters have a built-in function of calibrating at two points, either manually or automatically, this depends on the meter itself. When performing a manual calibration of the measuring equipment, the user must calibrate the value of the equipment to that of the buffer solution using a potentiometer.

On the other hand, in automatic calibration, the device recognizes the value of the buffer solution on its own and also adjusts itself to it. Most equipment can calibrate both 1 single point and 2, plus some may include unscheduled points on the equipment.

What is the pH meter used for?

The pH meter has a fairly clear function and that of calculating the acidity or alkalinity of a substance , it is generally used in large amounts of water. Among the main uses of the pH meter can be counted: swimming pools, drinking water, wells for agriculture, water for livestock, wells for feeding or cooking.

PH meters play an essential role when it comes to health issues , be it in water, food, skin and even soil; pH in high concentrations can be harmful and thanks to this the pH meter becomes indispensable in everyday life.The meters can also be used for the examination of shampoo, soap, toothpastes, medicines and food, thanks to this they can sell these products without being risky to humans.

Types of pH meters

The pH meters have different models which can be adapted to different needs; There are exactly 3 types of gauges, each with different specifications that make them indispensable tools. These types of meters are:

  • Portable pH meters. Due to their small size, they offer a portable handling function that makes them ideal for field or laboratory work . They offer different usable resources such as RS232 output, selection between degrees Celsius or Fahrenheit, setting of automatic data reading, indication of overload, automatic disconnection and automatic or manual compensation for temperature and other factors.
  • Bench pH meters. These are mostly used in laboratories, industries and manufacturing processes (As previously mentioned for shampoo and soaps). These meters offer functions that allow you to measure ions, temperatures, and mV. Meters are available that can range from the most sophisticated to the least tolerant (least sensitive to pH).
  • PH electrodes. Its use is seen mainly in laboratories and industrialization. One detail about this type of meter is that they are made of glass, because of this they are fragile and must be handled delicately. These electrodes are mainly used to measure aqueous media by projection. They are not usually used in solvents since they rarely have free hydrogen ions (which is what these devices measure specifically).

PH meter buffers

These solutions contain constant levels of pH and are able to withstand the changes that can occur at a much higher pH level. The main function of the buffer solutions is the calibration of the pH meters ( Electrode and meter ).

In the case of electrodes, they can present different results, not to mention that their efficiency can change over time, due to this it must be calibrated with the buffer solution periodically to avoid long-term errors.

Buffer solutions can be adjusted to a wide range of pH values, and can be used either in premixed solutions or in dry powder capsules that are much more widely used. Almost all meters require calibration at certain specific pH values.

In general, these calibrations are carried out near isopotential values (or neutral, that is to say 7 generally), while the second point is located at values ​​equal to 10 or 4. The most advisable thing is to verify that the calibration is carried out with a value of solution close to the pH being measured.

Possible drawbacks

When using pH meters there may be certain drawbacks that can be avoided with good handling of the device. The main situations that could arise when using a pH meter are:

  • Failure to thoroughly remove all residue from previously collected samples will contaminate the result of other samples taken in the future.
  • Electrode meters are much more sensitive and require only dry powder capsules for their calibration; Although it is somewhat problematic, it has a solution depending on the uses that are applied to it and generally the capsules are also much more used than the premixed solutions.
  • If the equipment is handled improperly or roughly, it can become out of calibration; To avoid this, it is necessary to use it correctly and delicately.
  • Whenever a sample is taken, it is necessary to wait before measuring a different one, since the equipment must dry even after cleaning it so that any residue ends up disappearing from the equipment; it can sometimes result in a delay when working with only one meter, so having more than one available is recommended.

Although there are some obstacles to use, pH meters are an excellent tool and allow easy calculations. With the benefit of working in a completely digital way, the pH meter ends up becoming a simply indispensable instrument.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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