pH Meter / pH Tester

Soil pH is undoubtedly one of the most important factors influencing the yield of any crop, along with other more obvious and well-known factors, such as water availability or plant nutrient content. It is not in vain that the pH value of a soil can cause certain nutrients and trace elements that are essential for a given crop to be in a form that can be assimilated by the plant, or vice versa: an unsuitable or inadequately controlled pH of the soil can cause nutrients that were originally available in the soil, or that the farmer has subsequently added through fertilization, to be in the form of a chemical compound that cannot be absorbed by the plant, and consequently the plant will not achieve its optimal development.

For this reason, and because of the inefficient use of expensive fertilizers, the farmer's profitability can be seriously compromised if he does not monitor the pH level of the soil with an appropriate pH meter. The latter will allow him to make the appropriate corrective decisions in each case. There are several known agronomic techniques that allow correcting the pH of the soil and adapting it to the optimal conditions of the crop. It must be taken into account that each crop has adequate intervals of the soil pH in which it is appropriate to work for an optimum performance. Although as a general rule most crops perform better in the soil in which the pH level is close to neutral or slightly acid, there are crops adapted and especially suitable for more acidic or more basic soils, away from neutral pH.

Without a doubt, one of the key factors providing a healthy and successful growth of the plants in a garden (without any nutritional deficiencies or phytosanitary problems) is the optimal for the plants, or at least acceptable pH value of the soil. However, when problems begin to appear, such as loss of the leaf color, or weak growth, one of the first factors to check is the pH level of the soil. This is why it is so important to pay a lot of attention to the pH of the garden soil. Unless extreme values are concerned, just an inadequate pH level alone is generally not the only reason that negatively influences the life of the plants, but it can affect their growth, depending on the degree of sensitivity of the plant. In fact, many plants are capable of adapting to a relatively wide range of pH levels. Hydrangeas, for example, produce flowers of different colors depending on whether they are grown in acid or alkaline soil.

It is very useful for the gardener to know whether the soil in his garden is alkaline or acidic, because certain nutrients can only be absorbed by the plants when the soil pH is in an acceptable range. In fact, no matter how much fertilizer can be added to the garden soil, it will not improve the health of the plants until the pH value has been adjusted. Most plants prefer a neutral pH, between 6.2 and 7.0. However, there are many plants that have more specific pH needs, such as blueberries and azaleas, which like a more acidic soil, and lilacs and clematis, which prefer a more alkaline soil. There are even some, such as hydrangeas, which change the color of the flower depending on the pH of the soil, as mentioned above.

Measuring the soil pH value is important because it influences several soil factors that affect plant growth in a garden, such as soil bacteria, nutrient leaching, nutrient availability, toxic elements and soil structure. Bacterial activity, that releases nitrogen from organic matter and certain fertilizers, is particularly affected by the pH of the garden soil, as bacteria perform best in the pH range of 5.5 to 7.0.

When you measure the pH of your garden soil with a pH meter and notice that it is beyond the desired range, you will need to take some steps to adjust it. In this way you will be able to adapt it to the particular needs of the plants in your garden. The soil that is too acidic is counteracted by applying e.g. limestone or finely ground wood ash, and alkaline soil can be treated with additives such as ground sulphur, ammonium sulphate or other acidifying fertilizers.

The pH value, a parameter defined by the concentration of hydrogen ions in an aqueous solution, has a determining influence on any chemical reaction taking place in that solution, to the extent that, depending on its value, it allows or does not allow a certain chemical reaction to take place. From this it can easily be deduced that both, the control and the handling of the pH value will be crucial, both in the control of the drinking water for human consumption and in the treatment of the waste water itself.

During the treatment of wastewater, the problem is essentially reduced to the elimination of all types of organic compounds and inorganic toxic elements (heavy metals, etc.) that may be present in the water as a result of urban use or industrial discharges.

In general, depending on the origin of the wastewater, the wastewater treatment process usually starts with purely physical processes to separate the larger elements (waste, organic or inorganic elements of the appropriate size, etc.). In these preparatory physical processes, such as sieving, filtering or decanting of the most easily separable fractions, the pH value does not play such a decisive role. However, from that moment on and in the following phases, the pH value (together with other basic parameters such as the presence of oxygen and temperature) will be decisive for the completion of the waste water treatment process.

The simple fact that the pH of the water is too low or, on the contrary, too high is in itself a decisive factor in ensuring that the water is not suitable for being discharged into the environment (lakes, rivers, etc.), let alone for human consumption. For this reason alone, it is necessary to control the pH of the water with a pH meter and to correct it if necessary. But its effects go much further in the purification processes. For example, in the removal of heavy metals and other toxic inorganic elements that could not be removed by the initial screening with physical means.

The pH value or the concentration of hydrogen ions or hydroxyl groups in the aqueous medium, depending on whether it is an acidic or alkaline medium, has a more than direct influence, for example, that a certain metal compound remains dissolved in the water, or on the contrary, that it reacts with the hydroxyl groups to form more or less insoluble salts and can thus finally be easily separated from the other components of the water by applying one of the physical methods originally described.

Each compound has certain pH values at which we can find it in one chemical form or another, so that the wise management and control of the pH value of the water by means of the suitable measuring instruments will mark the success or failure of the purification of certain elements.

Finally, the decisive influence of the pH value on the elimination of all types of pathogenic microorganisms is well known. These microorganisms, such as the enterobacterium Escherichia coli, can be present in the wastewater, e.g. through the discharge of the sewage or waste. A treatment that consists of bringing the pH below a certain level (depending on the pathogens we want to focus on) can be enormously effective in achieving our goals. It is obvious that after this treatment, it is essential to return the pH to the values that are closer to neutral and compatible with the rest of the living organisms before releasing it into the environment.

Especially when chlorinating water to make it suitable for the human consumption, to make it drinkable, the pH value is again crucial to whether the process is really effective or not. For reasons similar to those already mentioned for other inorganic compounds present in water, the pH-value will also be decisive in the case of chlorine for the formation of one or another type of compound and will make the difference as to whether chlorine actually develops its disinfecting effect or not. Besides other factors that can have an influence, such as water hardness, pH values below 6.5 - 6 or above 8 prevent the effectiveness of the process.

As is generally known, the pH is nothing more than a measure of the activity of hydrogen ions in a particular solution, and its value measured by a pH meter ultimately determines how acidic or alkaline the medium in which it is measured is. It is only when this first definition is taken into account that the first consequence of this parameter on the organoleptic quality of both food and fruit and vegetables is obvious: the acidity will ultimately be a determining factor in defining the taste of any food.

It is known that the acidity directly determines the taste of many raw materials, such as certain fruits. In fact, most foods, especially fruit, are acidic, i.e. with pH values below 7, which indicates neutrality. Only few foods are alkaline, i.e. with a pH value above 7.

But the pH not only makes the taste more or less acidic in the primary sense of the word, in many raw materials, but especially in other processed foods, which for example, in their production with fermentation processes (we would speak in this case of products such as wine or cheese), we find that the pH (almost always together with the temperature factor, which is usually closely related), this in turn will have a direct influence on such crucial parameters of organoleptic quality and taste of a food, such as e.g. the consistency of the food or the flavours of one kind or another that result from these fermentations.

The control of the pH value and therefore of the type of the microbial fauna that the fermentation process involves by using a pH meter can clearly make the difference between a product that is clearly recognizable and appreciated by the customer and for which he is prepared to pay a high price, and a product that is ready for direct disposal.

In addition to the mentioned above, there is one last factor where pH plays a crucial role in the agricultural and food sector, and that is food preservation. For example, it has been known for a long time that the use of vinegar is one of the most effective methods of preserving certain foods. This is because the high acidity preserves the food. As has been indicated earlier, almost all micro-organisms have an important sensitivity to the pH-value, and this includes in particular those micro-organisms (bacteria, fungi, etc.) that can be harmful to the food product and thus, spoil it for its marketing and consumption. A sufficiently low value on a pH meter can, if not completely inhibit the attack of harmful micro-organisms, at least minimize or delay this negative impact by extending the shelf life of the food, which can be done by the correct use of the other important parameters such as temperature (sterilization or freezing processes).

As a conclusion, it is clear that in the food and agricultural sector, and especially during the production process of more elaborate foods, it is essential to control the pH, either in a specific way at some critical points of the process using portable pH meter models or even with a pH meter with electrodes for continuous measurement, which allows a much more intensive control of the production if the process requires it.

The electrodes of a pH meter are generally designed for the measurement by direct immersion in an aqueous solution. However, for the measurement in certain solid foods, such as fruit, cheese or meat, pH meter devices with special electrodes (with blades) are already available on the market, with which they can be inserted directly into the food itself and measure its pH value.

An essential contribution to life in water is that it has the right pH value. In fact, for many aquatic organisms, life is only possible if the pH value is in the range of 5-9, for some organisms even in the narrower range of 6-8. This applies to both fauna and flora as well as aquatic plants. If the pH measured by a pH meter is too high or too low, wastewater can have very harmful effects on the environment into which it is discharged. In addition, several organisms are very sensitive to changes in the pH value. Wastewater must therefore be properly treated before it enters the rivers or lakes.

It should not be forgotten that certain bacteria and other organisms play an active role in wastewater treatment. In fact, it is very important for wastewater treatment plants to constantly monitor the pH value of the wastewater with a pH meter. The purpose of a wastewater treatment plant is to purify the wastewater. This is done through mechanical, biological and chemical treatments. The process of water purification requires all three types of treatment to be applied in sequence. However, only a pH value close to neutral or pH 7-value allows the microorganisms to act correctly and efficiently eliminate the nitrogen compounds and other impurities during the microbiological purification phase.

Measuring the pH value of the wastewater with a pH meter is also important for another reason. A too high or too low pH value can damage the pipes and technical equipment. Controlling the pH value with a pH meter also protects cement and metal from corrosion. For the industrial sector, it is essential to monitor the pH value of the wastewater with a pH meter. This prevents from having to deal with expensive repairs over some time.

There are many factors that influence the pH value of wastewater. In the private sector, the use of the cleaning products such as detergents, fabric softeners and other products must of course be considered. Many of these cleaning products are usually alkaline, with a pH value between 8 and 10, although there are also more acidic cleaning products. Depending on the type of dirtiness, one or the other type of product is used.

On the other hand, there is the industrial sector with its industrial discharges. Many industrial processes require the use of millions of liters of water per year. For example, bleach plants or fabric bleaching factories mainly produce rather acidic waste water. Metallurgy also discharges acidic water. All this shows that wastewater rarely has a neutral pH value. For this reason, it is necessary to neutralize the waste water. The use of a pH meter, whether it is a fixed or portable installation, makes it possible to determine the most suitable water treatment.